SLIDE 1
61A Lecture 22 Announcements Linked Lists Recursive Lists Can - - PowerPoint PPT Presentation
61A Lecture 22 Announcements Linked Lists Recursive Lists Can - - PowerPoint PPT Presentation
61A Lecture 22 Announcements Linked Lists Recursive Lists Can Change Attribute assignment statements can change first and rest attributes of a Link 4 Recursive Lists Can Change Attribute assignment statements can change first and rest
SLIDE 2
SLIDE 3
Linked Lists
SLIDE 4
Recursive Lists Can Change
Attribute assignment statements can change first and rest attributes of a Link
4
SLIDE 5
Recursive Lists Can Change
Attribute assignment statements can change first and rest attributes of a Link
4
The rest of a linked list can contain the linked list as a sub-list
SLIDE 6
>>> s = Link(1, Link(2, Link(3)))
Recursive Lists Can Change
Attribute assignment statements can change first and rest attributes of a Link
4
The rest of a linked list can contain the linked list as a sub-list
SLIDE 7
>>> s = Link(1, Link(2, Link(3)))
Recursive Lists Can Change
Attribute assignment statements can change first and rest attributes of a Link
4
The rest of a linked list can contain the linked list as a sub-list
Rest First
1
s Rest First
2
Global frame Rest First
3
SLIDE 8
>>> s = Link(1, Link(2, Link(3)))
Recursive Lists Can Change
Attribute assignment statements can change first and rest attributes of a Link
4
The rest of a linked list can contain the linked list as a sub-list Note: The actual environment diagram is much more complicated.
Rest First
1
s Rest First
2
Global frame Rest First
3
SLIDE 9
>>> s = Link(1, Link(2, Link(3)))
Recursive Lists Can Change
Attribute assignment statements can change first and rest attributes of a Link
4
The rest of a linked list can contain the linked list as a sub-list Note: The actual environment diagram is much more complicated.
SLIDE 10
>>> s = Link(1, Link(2, Link(3))) >>> s.first = 5
Recursive Lists Can Change
Attribute assignment statements can change first and rest attributes of a Link
4
The rest of a linked list can contain the linked list as a sub-list Note: The actual environment diagram is much more complicated.
SLIDE 11
>>> s = Link(1, Link(2, Link(3))) >>> s.first = 5 >>> t = s.rest
Recursive Lists Can Change
Attribute assignment statements can change first and rest attributes of a Link
4
The rest of a linked list can contain the linked list as a sub-list Note: The actual environment diagram is much more complicated.
SLIDE 12
>>> s = Link(1, Link(2, Link(3))) >>> s.first = 5 >>> t = s.rest >>> t.rest = s
Recursive Lists Can Change
Attribute assignment statements can change first and rest attributes of a Link
4
The rest of a linked list can contain the linked list as a sub-list Note: The actual environment diagram is much more complicated.
SLIDE 13
>>> s = Link(1, Link(2, Link(3))) >>> s.first = 5 >>> t = s.rest >>> t.rest = s >>> s.first
Recursive Lists Can Change
Attribute assignment statements can change first and rest attributes of a Link
4
The rest of a linked list can contain the linked list as a sub-list Note: The actual environment diagram is much more complicated.
SLIDE 14
>>> s = Link(1, Link(2, Link(3))) >>> s.first = 5 >>> t = s.rest >>> t.rest = s >>> s.first 5
Recursive Lists Can Change
Attribute assignment statements can change first and rest attributes of a Link
4
The rest of a linked list can contain the linked list as a sub-list Note: The actual environment diagram is much more complicated.
SLIDE 15
>>> s = Link(1, Link(2, Link(3))) >>> s.first = 5 >>> t = s.rest >>> t.rest = s >>> s.first 5 >>> s.rest.rest.rest.rest.rest.first
Recursive Lists Can Change
Attribute assignment statements can change first and rest attributes of a Link
4
The rest of a linked list can contain the linked list as a sub-list Note: The actual environment diagram is much more complicated.
SLIDE 16
>>> s = Link(1, Link(2, Link(3))) >>> s.first = 5 >>> t = s.rest >>> t.rest = s >>> s.first 5 >>> s.rest.rest.rest.rest.rest.first 2
Recursive Lists Can Change
Attribute assignment statements can change first and rest attributes of a Link
4
The rest of a linked list can contain the linked list as a sub-list Note: The actual environment diagram is much more complicated.
SLIDE 17
>>> s = Link(1, Link(2, Link(3))) >>> s.first = 5 >>> t = s.rest >>> t.rest = s >>> s.first 5 >>> s.rest.rest.rest.rest.rest.first 2
Recursive Lists Can Change
Attribute assignment statements can change first and rest attributes of a Link
4
Rest First
5
s Rest First
2
t Global frame
The rest of a linked list can contain the linked list as a sub-list Note: The actual environment diagram is much more complicated.
SLIDE 18
Environment Diagrams
SLIDE 19
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] Return Value Return Value Return Value
SLIDE 20
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski Return Value Return Value Return Value [parent=G]
SLIDE 21
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear Return Value Return Value Return Value [parent=G]
SLIDE 22
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear func abs(...) [parent=G] Return Value Return Value Return Value [parent=G]
SLIDE 23
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear func abs(...) [parent=G] Return Value Return Value Return Value cal func cal(berk) [parent=f1] [parent=G]
SLIDE 24
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear func abs(...) [parent=G] Return Value Return Value Return Value cal func cal(berk) [parent=f1] [parent=G]
SLIDE 25
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear func abs(...) [parent=G] Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal [parent=G]
SLIDE 26
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear func abs(...) [parent=G] Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal [parent=f1] [parent=G]
SLIDE 27
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear func abs(...) [parent=G] Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal [parent=f1] berk 2 [parent=G]
SLIDE 28
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear func abs(...) [parent=G] Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal func λ(ley) [parent=f2] [parent=f1] berk 2 [parent=G]
SLIDE 29
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear func abs(...) [parent=G] Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal func λ(ley) [parent=f2] [parent=f1] berk 2 [parent=G]
SLIDE 30
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear func abs(...) [parent=G] Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal func λ(ley) [parent=f2] [parent=f1] berk 2 [parent=G]
SLIDE 31
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal func λ(ley) [parent=f2] [parent=f1] berk 2 [parent=G]
SLIDE 32
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal func λ(ley) [parent=f2] [parent=f1] berk 2 [parent=G]
SLIDE 33
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal func λ(ley) [parent=f2] [parent=f1] berk 2 [parent=G]
SLIDE 34
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal func λ(ley) [parent=f2] [parent=f1] berk 2 [parent=G]
SLIDE 35
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal func λ(ley) [parent=f2] [parent=f1] berk 2 [parent=G]
SLIDE 36
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal func λ(ley) [parent=f2] [parent=f1] berk 2 [parent=G]
SLIDE 37
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal func λ(ley) [parent=f2] [parent=f1] berk 2 [parent=G]
SLIDE 38
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal func λ(ley) [parent=f2] [parent=f1] berk 2 f3: cal [parent=G]
SLIDE 39
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal func λ(ley) [parent=f2] [parent=f1] berk 2 f3: cal [parent=f1] [parent=G]
SLIDE 40
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal func λ(ley) [parent=f2] [parent=f1] berk 2 f3: cal [parent=f1] 2 berk [parent=G]
SLIDE 41
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal func λ(ley) [parent=f2] [parent=f1] berk 2 f3: cal [parent=f1] 2 berk [parent=G]
SLIDE 42
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal func λ(ley) [parent=f2] [parent=f1] berk 2 f3: cal [parent=f1] 2 berk [parent=G]
SLIDE 43
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal func λ(ley) [parent=f2] [parent=f1] berk 2 f3: cal [parent=f1] 2 berk f4: λ [parent=G]
SLIDE 44
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal func λ(ley) [parent=f2] [parent=f1] berk 2 f3: cal [parent=f1] 2 berk f4: λ [parent=f2] [parent=G]
SLIDE 45
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal func λ(ley) [parent=f2] [parent=f1] berk 2 f3: cal [parent=f1] 2 berk f4: λ [parent=f2] ley 2 [parent=G]
SLIDE 46
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal func λ(ley) [parent=f2] [parent=f1] berk 2 f3: cal [parent=f1] 2 berk f4: λ [parent=f2] ley 2 [parent=G]
SLIDE 47
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal func λ(ley) [parent=f2] [parent=f1] berk 2 f3: cal [parent=f1] 2 berk f4: λ [parent=f2] ley 2 [parent=G]
SLIDE 48
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal func λ(ley) [parent=f2] [parent=f1] berk 2 f3: cal [parent=f1] 2 berk list 1
3 1
f4: λ [parent=f2] ley 2 [parent=G]
SLIDE 49
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal func λ(ley) [parent=f2] [parent=f1] berk 2 f3: cal [parent=f1] 2 berk list 1
3 1
f4: λ [parent=f2] list 1
2
ley 2 [parent=G]
SLIDE 50
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal func λ(ley) [parent=f2] [parent=f1] berk 2 f3: cal [parent=f1] 2 berk list 1
3 1
f4: λ [parent=f2] list 1
2
ley 2 [parent=G]
SLIDE 51
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal func λ(ley) [parent=f2] [parent=f1] berk 2 f3: cal [parent=f1] 2 berk list 1
3 1
f4: λ [parent=f2] list 1
2
ley 2 [parent=G]
SLIDE 52
Go Bears!
6
def oski(bear): def cal(berk): nonlocal bear if bear(berk) == 0: return [berk+1, berk-1] bear = lambda ley: berk-ley return [berk, cal(berk)] return cal(2)
- ski(abs)
Return Value Global frame
- ski
func oski(bear)[parent=G] f1: oski bear Return Value Return Value Return Value cal func cal(berk) [parent=f1] f2: cal func λ(ley) [parent=f2] [parent=f1] berk 2 f3: cal [parent=f1] 2 berk list 1
3 1
f4: λ [parent=f2] list 1
2
ley 2 [parent=G]
[2, [3, 1]]
SLIDE 53
Objects
SLIDE 54
Land Owners
Instance attributes are found before class attributes; class attributes are inherited
8
SLIDE 55
Land Owners
Instance attributes are found before class attributes; class attributes are inherited
8
class Worker:
SLIDE 56
Land Owners
Instance attributes are found before class attributes; class attributes are inherited
8
class Worker: greeting = 'Sir'
SLIDE 57
Land Owners
Instance attributes are found before class attributes; class attributes are inherited
8
class Worker: greeting = 'Sir' def __init__(self): self.elf = Worker
SLIDE 58
Land Owners
Instance attributes are found before class attributes; class attributes are inherited
8
class Worker: greeting = 'Sir' def __init__(self): self.elf = Worker def work(self): return self.greeting + ', I work'
SLIDE 59
Land Owners
Instance attributes are found before class attributes; class attributes are inherited
8
class Worker: greeting = 'Sir' def __init__(self): self.elf = Worker def work(self): return self.greeting + ', I work' def __repr__(self): return Bourgeoisie.greeting
SLIDE 60
Land Owners
Instance attributes are found before class attributes; class attributes are inherited
8
class Worker: greeting = 'Sir' def __init__(self): self.elf = Worker def work(self): return self.greeting + ', I work' def __repr__(self): return Bourgeoisie.greeting class Bourgeoisie(Worker):
SLIDE 61
Land Owners
Instance attributes are found before class attributes; class attributes are inherited
8
class Worker: greeting = 'Sir' def __init__(self): self.elf = Worker def work(self): return self.greeting + ', I work' def __repr__(self): return Bourgeoisie.greeting class Bourgeoisie(Worker): greeting = 'Peon'
SLIDE 62
Land Owners
Instance attributes are found before class attributes; class attributes are inherited
8
class Worker: greeting = 'Sir' def __init__(self): self.elf = Worker def work(self): return self.greeting + ', I work' def __repr__(self): return Bourgeoisie.greeting class Bourgeoisie(Worker): greeting = 'Peon' def work(self): print(Worker.work(self)) return 'I gather wealth'
SLIDE 63
Land Owners
Instance attributes are found before class attributes; class attributes are inherited
8
class Worker: greeting = 'Sir' def __init__(self): self.elf = Worker def work(self): return self.greeting + ', I work' def __repr__(self): return Bourgeoisie.greeting class Bourgeoisie(Worker): greeting = 'Peon' def work(self): print(Worker.work(self)) return 'I gather wealth' jack = Worker() john = Bourgeoisie() jack.greeting = 'Maam'
SLIDE 64
>>> Worker().work() >>> jack >>> jack.work() >>> john.work() >>> john.elf.work(john)
Land Owners
Instance attributes are found before class attributes; class attributes are inherited
8
class Worker: greeting = 'Sir' def __init__(self): self.elf = Worker def work(self): return self.greeting + ', I work' def __repr__(self): return Bourgeoisie.greeting class Bourgeoisie(Worker): greeting = 'Peon' def work(self): print(Worker.work(self)) return 'I gather wealth' jack = Worker() john = Bourgeoisie() jack.greeting = 'Maam'
SLIDE 65
>>> Worker().work() >>> jack >>> jack.work() >>> john.work() >>> john.elf.work(john)
Land Owners
Instance attributes are found before class attributes; class attributes are inherited
8
class Worker: greeting = 'Sir' def __init__(self): self.elf = Worker def work(self): return self.greeting + ', I work' def __repr__(self): return Bourgeoisie.greeting class Bourgeoisie(Worker): greeting = 'Peon' def work(self): print(Worker.work(self)) return 'I gather wealth' jack = Worker() john = Bourgeoisie() jack.greeting = 'Maam' <class Worker> greeting: 'Sir'
SLIDE 66
>>> Worker().work() >>> jack >>> jack.work() >>> john.work() >>> john.elf.work(john)
Land Owners
Instance attributes are found before class attributes; class attributes are inherited
8
class Worker: greeting = 'Sir' def __init__(self): self.elf = Worker def work(self): return self.greeting + ', I work' def __repr__(self): return Bourgeoisie.greeting class Bourgeoisie(Worker): greeting = 'Peon' def work(self): print(Worker.work(self)) return 'I gather wealth' jack = Worker() john = Bourgeoisie() jack.greeting = 'Maam' <class Worker> greeting: 'Sir' <class Bourgeoisie> greeting: 'Peon'
SLIDE 67
>>> Worker().work() >>> jack >>> jack.work() >>> john.work() >>> john.elf.work(john) jack <Worker> elf:
Land Owners
Instance attributes are found before class attributes; class attributes are inherited
8
class Worker: greeting = 'Sir' def __init__(self): self.elf = Worker def work(self): return self.greeting + ', I work' def __repr__(self): return Bourgeoisie.greeting class Bourgeoisie(Worker): greeting = 'Peon' def work(self): print(Worker.work(self)) return 'I gather wealth' jack = Worker() john = Bourgeoisie() jack.greeting = 'Maam' <class Worker> greeting: 'Sir' <class Bourgeoisie> greeting: 'Peon'
SLIDE 68
>>> Worker().work() >>> jack >>> jack.work() >>> john.work() >>> john.elf.work(john) jack <Worker> elf:
Land Owners
Instance attributes are found before class attributes; class attributes are inherited
8
class Worker: greeting = 'Sir' def __init__(self): self.elf = Worker def work(self): return self.greeting + ', I work' def __repr__(self): return Bourgeoisie.greeting class Bourgeoisie(Worker): greeting = 'Peon' def work(self): print(Worker.work(self)) return 'I gather wealth' jack = Worker() john = Bourgeoisie() jack.greeting = 'Maam' <class Worker> greeting: 'Sir' <class Bourgeoisie> greeting: 'Peon' elf: john <Bourgeoisie>
SLIDE 69
>>> Worker().work() >>> jack >>> jack.work() >>> john.work() >>> john.elf.work(john) jack <Worker> elf:
Land Owners
Instance attributes are found before class attributes; class attributes are inherited
8
class Worker: greeting = 'Sir' def __init__(self): self.elf = Worker def work(self): return self.greeting + ', I work' def __repr__(self): return Bourgeoisie.greeting class Bourgeoisie(Worker): greeting = 'Peon' def work(self): print(Worker.work(self)) return 'I gather wealth' jack = Worker() john = Bourgeoisie() jack.greeting = 'Maam' <class Worker> greeting: 'Sir' <class Bourgeoisie> greeting: 'Peon' greeting: 'Maam' elf: john <Bourgeoisie>
SLIDE 70
>>> Worker().work() >>> jack >>> jack.work() >>> john.work() >>> john.elf.work(john) jack <Worker> elf:
Land Owners
Instance attributes are found before class attributes; class attributes are inherited
8
class Worker: greeting = 'Sir' def __init__(self): self.elf = Worker def work(self): return self.greeting + ', I work' def __repr__(self): return Bourgeoisie.greeting class Bourgeoisie(Worker): greeting = 'Peon' def work(self): print(Worker.work(self)) return 'I gather wealth' jack = Worker() john = Bourgeoisie() jack.greeting = 'Maam' >>> Worker().work() <class Worker> greeting: 'Sir' <class Bourgeoisie> greeting: 'Peon' greeting: 'Maam' elf: john <Bourgeoisie>
SLIDE 71
>>> Worker().work() >>> jack >>> jack.work() >>> john.work() >>> john.elf.work(john) jack <Worker> elf:
Land Owners
Instance attributes are found before class attributes; class attributes are inherited
8
class Worker: greeting = 'Sir' def __init__(self): self.elf = Worker def work(self): return self.greeting + ', I work' def __repr__(self): return Bourgeoisie.greeting class Bourgeoisie(Worker): greeting = 'Peon' def work(self): print(Worker.work(self)) return 'I gather wealth' jack = Worker() john = Bourgeoisie() jack.greeting = 'Maam' >>> Worker().work() 'Sir, I work' <class Worker> greeting: 'Sir' <class Bourgeoisie> greeting: 'Peon' greeting: 'Maam' elf: john <Bourgeoisie>
SLIDE 72
>>> Worker().work() >>> jack >>> jack.work() >>> john.work() >>> john.elf.work(john) jack <Worker> elf:
Land Owners
Instance attributes are found before class attributes; class attributes are inherited
8
class Worker: greeting = 'Sir' def __init__(self): self.elf = Worker def work(self): return self.greeting + ', I work' def __repr__(self): return Bourgeoisie.greeting class Bourgeoisie(Worker): greeting = 'Peon' def work(self): print(Worker.work(self)) return 'I gather wealth' jack = Worker() john = Bourgeoisie() jack.greeting = 'Maam' >>> Worker().work() 'Sir, I work' >>> jack <class Worker> greeting: 'Sir' <class Bourgeoisie> greeting: 'Peon' greeting: 'Maam' elf: john <Bourgeoisie>
SLIDE 73
>>> Worker().work() >>> jack >>> jack.work() >>> john.work() >>> john.elf.work(john) jack <Worker> elf:
Land Owners
Instance attributes are found before class attributes; class attributes are inherited
8
class Worker: greeting = 'Sir' def __init__(self): self.elf = Worker def work(self): return self.greeting + ', I work' def __repr__(self): return Bourgeoisie.greeting class Bourgeoisie(Worker): greeting = 'Peon' def work(self): print(Worker.work(self)) return 'I gather wealth' jack = Worker() john = Bourgeoisie() jack.greeting = 'Maam' >>> Worker().work() 'Sir, I work' >>> jack Peon <class Worker> greeting: 'Sir' <class Bourgeoisie> greeting: 'Peon' greeting: 'Maam' elf: john <Bourgeoisie>
SLIDE 74
>>> Worker().work() >>> jack >>> jack.work() >>> john.work() >>> john.elf.work(john) jack <Worker> elf:
Land Owners
Instance attributes are found before class attributes; class attributes are inherited
8
class Worker: greeting = 'Sir' def __init__(self): self.elf = Worker def work(self): return self.greeting + ', I work' def __repr__(self): return Bourgeoisie.greeting class Bourgeoisie(Worker): greeting = 'Peon' def work(self): print(Worker.work(self)) return 'I gather wealth' jack = Worker() john = Bourgeoisie() jack.greeting = 'Maam' >>> Worker().work() 'Sir, I work' >>> jack Peon >>> jack.work() <class Worker> greeting: 'Sir' <class Bourgeoisie> greeting: 'Peon' greeting: 'Maam' elf: john <Bourgeoisie>
SLIDE 75
>>> Worker().work() >>> jack >>> jack.work() >>> john.work() >>> john.elf.work(john) jack <Worker> elf:
Land Owners
Instance attributes are found before class attributes; class attributes are inherited
8
class Worker: greeting = 'Sir' def __init__(self): self.elf = Worker def work(self): return self.greeting + ', I work' def __repr__(self): return Bourgeoisie.greeting class Bourgeoisie(Worker): greeting = 'Peon' def work(self): print(Worker.work(self)) return 'I gather wealth' jack = Worker() john = Bourgeoisie() jack.greeting = 'Maam' >>> Worker().work() 'Sir, I work' >>> jack Peon >>> jack.work() 'Maam, I work' <class Worker> greeting: 'Sir' <class Bourgeoisie> greeting: 'Peon' greeting: 'Maam' elf: john <Bourgeoisie>
SLIDE 76
>>> Worker().work() >>> jack >>> jack.work() >>> john.work() >>> john.elf.work(john) jack <Worker> elf:
Land Owners
Instance attributes are found before class attributes; class attributes are inherited
8
class Worker: greeting = 'Sir' def __init__(self): self.elf = Worker def work(self): return self.greeting + ', I work' def __repr__(self): return Bourgeoisie.greeting class Bourgeoisie(Worker): greeting = 'Peon' def work(self): print(Worker.work(self)) return 'I gather wealth' jack = Worker() john = Bourgeoisie() jack.greeting = 'Maam' >>> Worker().work() 'Sir, I work' >>> jack Peon >>> jack.work() 'Maam, I work' >>> john.work() <class Worker> greeting: 'Sir' <class Bourgeoisie> greeting: 'Peon' greeting: 'Maam' elf: john <Bourgeoisie>
SLIDE 77
>>> Worker().work() >>> jack >>> jack.work() >>> john.work() >>> john.elf.work(john) jack <Worker> elf:
Land Owners
Instance attributes are found before class attributes; class attributes are inherited
8
class Worker: greeting = 'Sir' def __init__(self): self.elf = Worker def work(self): return self.greeting + ', I work' def __repr__(self): return Bourgeoisie.greeting class Bourgeoisie(Worker): greeting = 'Peon' def work(self): print(Worker.work(self)) return 'I gather wealth' jack = Worker() john = Bourgeoisie() jack.greeting = 'Maam' >>> Worker().work() 'Sir, I work' >>> jack Peon >>> jack.work() 'Maam, I work' >>> john.work() Peon, I work 'I gather wealth' <class Worker> greeting: 'Sir' <class Bourgeoisie> greeting: 'Peon' greeting: 'Maam' elf: john <Bourgeoisie>
SLIDE 78
>>> Worker().work() >>> jack >>> jack.work() >>> john.work() >>> john.elf.work(john) jack <Worker> elf:
Land Owners
Instance attributes are found before class attributes; class attributes are inherited
8
class Worker: greeting = 'Sir' def __init__(self): self.elf = Worker def work(self): return self.greeting + ', I work' def __repr__(self): return Bourgeoisie.greeting class Bourgeoisie(Worker): greeting = 'Peon' def work(self): print(Worker.work(self)) return 'I gather wealth' jack = Worker() john = Bourgeoisie() jack.greeting = 'Maam' >>> Worker().work() 'Sir, I work' >>> jack Peon >>> jack.work() 'Maam, I work' >>> john.work() Peon, I work 'I gather wealth' >>> john.elf.work(john) <class Worker> greeting: 'Sir' <class Bourgeoisie> greeting: 'Peon' greeting: 'Maam' elf: john <Bourgeoisie>
SLIDE 79
>>> Worker().work() >>> jack >>> jack.work() >>> john.work() >>> john.elf.work(john) jack <Worker> elf:
Land Owners
Instance attributes are found before class attributes; class attributes are inherited
8
class Worker: greeting = 'Sir' def __init__(self): self.elf = Worker def work(self): return self.greeting + ', I work' def __repr__(self): return Bourgeoisie.greeting class Bourgeoisie(Worker): greeting = 'Peon' def work(self): print(Worker.work(self)) return 'I gather wealth' jack = Worker() john = Bourgeoisie() jack.greeting = 'Maam' >>> Worker().work() 'Sir, I work' >>> jack Peon >>> jack.work() 'Maam, I work' >>> john.work() Peon, I work 'I gather wealth' >>> john.elf.work(john) 'Peon, I work' <class Worker> greeting: 'Sir' <class Bourgeoisie> greeting: 'Peon' greeting: 'Maam' elf: john <Bourgeoisie>
SLIDE 80
Trees
SLIDE 81
Morse Code
Morse code is a signaling protocol that transmits messages by sequences of signals
10
SLIDE 82
Morse Code
Morse code is a signaling protocol that transmits messages by sequences of signals
10
A: B: C: D: E: ...
SLIDE 83
Morse Code
Morse code is a signaling protocol that transmits messages by sequences of signals
10
A: B: C: D: E: ... Problem: Implement morse so that decode works correctly
SLIDE 84
Morse Code
Morse code is a signaling protocol that transmits messages by sequences of signals
10
A: B: C: D: E: ... Problem: Implement morse so that decode works correctly abcde = {'a': '.-', 'b': '-...', 'c': '-.-.', 'd': '-..', 'e': '.'}
SLIDE 85
Morse Code
Morse code is a signaling protocol that transmits messages by sequences of signals
10
A: B: C: D: E: ... Problem: Implement morse so that decode works correctly abcde = {'a': '.-', 'b': '-...', 'c': '-.-.', 'd': '-..', 'e': '.'}
def decode(signals, tree): """Decode signals into a letter. >>> t = morse(abcde) >>> [decode(s, t) for s in ['-..', '.', '-.-.', '.-', '-..', '.']] ['d', 'e', 'c', 'a', 'd', 'e'] """ for signal in signals: tree = [b for b in tree.branches if b.root == signal][0] leaves = [b for b in tree.branches if b.is_leaf()] assert len(leaves) == 1 return leaves[0].root
SLIDE 86
Morse Code
Morse code is a signaling protocol that transmits messages by sequences of signals
10
A: B: C: D: E: ... Problem: Implement morse so that decode works correctly abcde = {'a': '.-', 'b': '-...', 'c': '-.-.', 'd': '-..', 'e': '.'}
def decode(signals, tree): """Decode signals into a letter. >>> t = morse(abcde) >>> [decode(s, t) for s in ['-..', '.', '-.-.', '.-', '-..', '.']] ['d', 'e', 'c', 'a', 'd', 'e'] """ for signal in signals: tree = [b for b in tree.branches if b.root == signal][0] leaves = [b for b in tree.branches if b.is_leaf()] assert len(leaves) == 1 return leaves[0].root
def morse(code): ....
SLIDE 87
Morse Code
Morse code is a signaling protocol that transmits messages by sequences of signals
10
A: B: C: D: E: ... Problem: Implement morse so that decode works correctly abcde = {'a': '.-', 'b': '-...', 'c': '-.-.', 'd': '-..', 'e': '.'}
def decode(signals, tree): """Decode signals into a letter. >>> t = morse(abcde) >>> [decode(s, t) for s in ['-..', '.', '-.-.', '.-', '-..', '.']] ['d', 'e', 'c', 'a', 'd', 'e'] """ for signal in signals: tree = [b for b in tree.branches if b.root == signal][0] leaves = [b for b in tree.branches if b.is_leaf()] assert len(leaves) == 1 return leaves[0].root
def morse(code): ....
SLIDE 88
Morse Code
Morse code is a signaling protocol that transmits messages by sequences of signals
10
A: B: C: D: E: ... Problem: Implement morse so that decode works correctly abcde = {'a': '.-', 'b': '-...', 'c': '-.-.', 'd': '-..', 'e': '.'}
def decode(signals, tree): """Decode signals into a letter. >>> t = morse(abcde) >>> [decode(s, t) for s in ['-..', '.', '-.-.', '.-', '-..', '.']] ['d', 'e', 'c', 'a', 'd', 'e'] """ for signal in signals: tree = [b for b in tree.branches if b.root == signal][0] leaves = [b for b in tree.branches if b.is_leaf()] assert len(leaves) == 1 return leaves[0].root
def morse(code): .... decode('.', t)
SLIDE 89
Morse Code
Morse code is a signaling protocol that transmits messages by sequences of signals
10
A: B: C: D: E: ... Problem: Implement morse so that decode works correctly abcde = {'a': '.-', 'b': '-...', 'c': '-.-.', 'd': '-..', 'e': '.'}
def decode(signals, tree): """Decode signals into a letter. >>> t = morse(abcde) >>> [decode(s, t) for s in ['-..', '.', '-.-.', '.-', '-..', '.']] ['d', 'e', 'c', 'a', 'd', 'e'] """ for signal in signals: tree = [b for b in tree.branches if b.root == signal][0] leaves = [b for b in tree.branches if b.is_leaf()] assert len(leaves) == 1 return leaves[0].root
def morse(code): .... decode('.', t)
SLIDE 90
Morse Code
Morse code is a signaling protocol that transmits messages by sequences of signals
10
A: B: C: D: E: ... Problem: Implement morse so that decode works correctly abcde = {'a': '.-', 'b': '-...', 'c': '-.-.', 'd': '-..', 'e': '.'}
def decode(signals, tree): """Decode signals into a letter. >>> t = morse(abcde) >>> [decode(s, t) for s in ['-..', '.', '-.-.', '.-', '-..', '.']] ['d', 'e', 'c', 'a', 'd', 'e'] """ for signal in signals: tree = [b for b in tree.branches if b.root == signal][0] leaves = [b for b in tree.branches if b.is_leaf()] assert len(leaves) == 1 return leaves[0].root
def morse(code): .... ? decode('.', t)
SLIDE 91
Morse Code
Morse code is a signaling protocol that transmits messages by sequences of signals
10
A: B: C: D: E: ... Problem: Implement morse so that decode works correctly abcde = {'a': '.-', 'b': '-...', 'c': '-.-.', 'd': '-..', 'e': '.'}
def decode(signals, tree): """Decode signals into a letter. >>> t = morse(abcde) >>> [decode(s, t) for s in ['-..', '.', '-.-.', '.-', '-..', '.']] ['d', 'e', 'c', 'a', 'd', 'e'] """ for signal in signals: tree = [b for b in tree.branches if b.root == signal][0] leaves = [b for b in tree.branches if b.is_leaf()] assert len(leaves) == 1 return leaves[0].root
def morse(code): .... ? '.' decode('.', t)
SLIDE 92
Morse Code
Morse code is a signaling protocol that transmits messages by sequences of signals
10
A: B: C: D: E: ... Problem: Implement morse so that decode works correctly abcde = {'a': '.-', 'b': '-...', 'c': '-.-.', 'd': '-..', 'e': '.'}
def decode(signals, tree): """Decode signals into a letter. >>> t = morse(abcde) >>> [decode(s, t) for s in ['-..', '.', '-.-.', '.-', '-..', '.']] ['d', 'e', 'c', 'a', 'd', 'e'] """ for signal in signals: tree = [b for b in tree.branches if b.root == signal][0] leaves = [b for b in tree.branches if b.is_leaf()] assert len(leaves) == 1 return leaves[0].root
def morse(code): .... ? '.' decode('.', t)
SLIDE 93
Morse Code
Morse code is a signaling protocol that transmits messages by sequences of signals
10
A: B: C: D: E: ... Problem: Implement morse so that decode works correctly abcde = {'a': '.-', 'b': '-...', 'c': '-.-.', 'd': '-..', 'e': '.'}
def decode(signals, tree): """Decode signals into a letter. >>> t = morse(abcde) >>> [decode(s, t) for s in ['-..', '.', '-.-.', '.-', '-..', '.']] ['d', 'e', 'c', 'a', 'd', 'e'] """ for signal in signals: tree = [b for b in tree.branches if b.root == signal][0] leaves = [b for b in tree.branches if b.is_leaf()] assert len(leaves) == 1 return leaves[0].root
def morse(code): .... ? '.' decode('.', t)
SLIDE 94
Morse Code
Morse code is a signaling protocol that transmits messages by sequences of signals
10
A: B: C: D: E: ... Problem: Implement morse so that decode works correctly abcde = {'a': '.-', 'b': '-...', 'c': '-.-.', 'd': '-..', 'e': '.'}
def decode(signals, tree): """Decode signals into a letter. >>> t = morse(abcde) >>> [decode(s, t) for s in ['-..', '.', '-.-.', '.-', '-..', '.']] ['d', 'e', 'c', 'a', 'd', 'e'] """ for signal in signals: tree = [b for b in tree.branches if b.root == signal][0] leaves = [b for b in tree.branches if b.is_leaf()] assert len(leaves) == 1 return leaves[0].root
def morse(code): .... ? '.' 'e' decode('.', t)
SLIDE 95
Morse Code
Morse code is a signaling protocol that transmits messages by sequences of signals
10
A: B: C: D: E: ... Problem: Implement morse so that decode works correctly abcde = {'a': '.-', 'b': '-...', 'c': '-.-.', 'd': '-..', 'e': '.'}
def decode(signals, tree): """Decode signals into a letter. >>> t = morse(abcde) >>> [decode(s, t) for s in ['-..', '.', '-.-.', '.-', '-..', '.']] ['d', 'e', 'c', 'a', 'd', 'e'] """ for signal in signals: tree = [b for b in tree.branches if b.root == signal][0] leaves = [b for b in tree.branches if b.is_leaf()] assert len(leaves) == 1 return leaves[0].root
def morse(code): .... ? '.' 'e'
SLIDE 96
Morse Code
Morse code is a signaling protocol that transmits messages by sequences of signals
10
A: B: C: D: E: ... Problem: Implement morse so that decode works correctly abcde = {'a': '.-', 'b': '-...', 'c': '-.-.', 'd': '-..', 'e': '.'}
def decode(signals, tree): """Decode signals into a letter. >>> t = morse(abcde) >>> [decode(s, t) for s in ['-..', '.', '-.-.', '.-', '-..', '.']] ['d', 'e', 'c', 'a', 'd', 'e'] """ for signal in signals: tree = [b for b in tree.branches if b.root == signal][0] leaves = [b for b in tree.branches if b.is_leaf()] assert len(leaves) == 1 return leaves[0].root
def morse(code): .... ? '.' 'e' '-'
SLIDE 97
Morse Code
Morse code is a signaling protocol that transmits messages by sequences of signals
10
A: B: C: D: E: ... Problem: Implement morse so that decode works correctly abcde = {'a': '.-', 'b': '-...', 'c': '-.-.', 'd': '-..', 'e': '.'}
def decode(signals, tree): """Decode signals into a letter. >>> t = morse(abcde) >>> [decode(s, t) for s in ['-..', '.', '-.-.', '.-', '-..', '.']] ['d', 'e', 'c', 'a', 'd', 'e'] """ for signal in signals: tree = [b for b in tree.branches if b.root == signal][0] leaves = [b for b in tree.branches if b.is_leaf()] assert len(leaves) == 1 return leaves[0].root
def morse(code): .... ? '.' 'e' '-' 'a'
SLIDE 98
Morse Code
Morse code is a signaling protocol that transmits messages by sequences of signals
10
A: B: C: D: E: ... Problem: Implement morse so that decode works correctly abcde = {'a': '.-', 'b': '-...', 'c': '-.-.', 'd': '-..', 'e': '.'}
def decode(signals, tree): """Decode signals into a letter. >>> t = morse(abcde) >>> [decode(s, t) for s in ['-..', '.', '-.-.', '.-', '-..', '.']] ['d', 'e', 'c', 'a', 'd', 'e'] """ for signal in signals: tree = [b for b in tree.branches if b.root == signal][0] leaves = [b for b in tree.branches if b.is_leaf()] assert len(leaves) == 1 return leaves[0].root
def morse(code): .... ? '.' 'e' '-' 'a' '-' ...
SLIDE 99
Morse Code
Morse code is a signaling protocol that transmits messages by sequences of signals
10