Looping through Python data structures Justin Kiggins Product - - PowerPoint PPT Presentation

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Looping through Python data structures Justin Kiggins Product - - PowerPoint PPT Presentation

Jul 17, 2023 22 likes •255 views

DataCamp Python for MATLAB Users PYTHON FOR MATLAB USERS Looping through Python data structures Justin Kiggins Product Manager DataCamp Python for MATLAB Users How for loops work in Python MATLAB Python for i=1:5 for i in [1, 2, 3, 4,

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DataCamp Python for MATLAB Users

Looping through Python data structures

PYTHON FOR MATLAB USERS

Justin Kiggins

Product Manager

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DataCamp Python for MATLAB Users

How for loops work in Python

MATLAB Python

for i=1:5 disp(i); end disp('done'); 1 2 3 4 5 done for i in [1, 2, 3, 4, 5]: print(i) print('done') 1 2 3 4 5 done

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DataCamp Python for MATLAB Users

Looping through a list of strings

groceries = ['bread', 'tea', 'banana'] print(groceries) ['bread', 'tea', 'banana'] for item in groceries: print(item) bread tea banana

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DataCamp Python for MATLAB Users

Looping through a dictionary

abbreviations = {'New York': 'NY', 'California': 'CA', 'Illinois': 'IL', 'Texas': 'TX'} print(abbreviations) {'New York': 'NY', 'California': 'CA', 'Illinois': 'IL', 'Texas': 'TX'} for state, abbv in abbreviations.items(): print(state, abbv) New York NY California CA Illinois IL Texas TX

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DataCamp Python for MATLAB Users

Looping through a 1D NumPy array

import numpy as np arr = np.array([1, 2, 3]) print(arr) [1 2 3] for element in arr: print(element) 1 2 3

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DataCamp Python for MATLAB Users

Looping through a 2D NumPy array

import numpy as np X = np.array([[1, 2, 3], [4, 5, 6]]) print(X) [[1 2 3] [4 5 6]] for row in X: print(row) [1 2 3] [4 5 6]

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DataCamp Python for MATLAB Users

Looping through pandas DataFrames

import pandas as pd d = [{'fruit': 'apple', 'color': 'red'}, {'fruit': 'banana', 'color': 'yellow'}, {'fruit': 'pear', 'color': 'green'}] df = pd.DataFrame(d) print(df) color fruit 0 red apple 1 yellow banana 2 green pear for ii, row in df.iterrows(): print(ii, row['fruit'], row['color']) 0 apple red 1 banana yellow 2 pear green

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DataCamp Python for MATLAB Users

Let's practice!

PYTHON FOR MATLAB USERS

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DataCamp Python for MATLAB Users

Comparison operators

PYTHON FOR MATLAB USERS

Justin Kiggins

Product Manager

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DataCamp Python for MATLAB Users

Using comparison operators

value = 0.967 threshold = 0.85 meets_criteria = value > threshold print(meets_criteria) True

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DataCamp Python for MATLAB Users

The comparison operators

Comparison Python MATLAB Equal

== ==

Not equal

!= ~=

Less than

< <

Less than or equal

<= <=

Greater than

> >

Greater than or equal

>= >=

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DataCamp Python for MATLAB Users

If

value = 0.967 threshold = 0.85 meets_criteria = value > threshold if meets_criteria: print('PASS') PASS

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DataCamp Python for MATLAB Users

Else

value = 0.275 threshold = 0.85 meets_criteria = value > threshold if meets_criteria: print('PASS') else: print('FAIL') FAIL

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DataCamp Python for MATLAB Users

Else if

porridge_temperature = 74.6 if porridge_temperature > 130: print('Too hot! :(') elif porridge_temperature < 110: print('Too cold! :(') else: print('Just right :D') Too cold! :(

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DataCamp Python for MATLAB Users

Let's practice

PYTHON FOR MATLAB USERS

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DataCamp Python for MATLAB Users

Filtering data

PYTHON FOR MATLAB USERS

Justin Kiggins

Product Manager

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DataCamp Python for MATLAB Users

Comparison operators and NumPy Arrays

data = np.array([0.967, 0.56, 0.171, 0.872]) threshold = 0.85 meets_criteria = data > threshold print(meets_criteria) [True, False, False, True]

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DataCamp Python for MATLAB Users

Filtering NumPy arrays

data = np.array([-1, 0.56, -1, 0.872, 1.26]) is_valid = data >= 0 valid_data = data[is_valid] print(valid_data) [0.56, 0.872, 1.26]

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DataCamp Python for MATLAB Users

Filtering DataFrames

monkeys = df['animal'] == 'monkey' bears = df['animal'] == 'bear' monkey_weight = df[monkeys]['weight'].mean() bear_weight = df[bears]['weight'].mean() print(monkey_weight) 35.0 print(bear_weight) 800.0

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DataCamp Python for MATLAB Users

Let's practice

PYTHON FOR MATLAB USERS

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DataCamp Python for MATLAB Users

Well done!

PYTHON FOR MATLAB USERS

Justin Kiggins

Product Manager

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DataCamp Python for MATLAB Users

More courses to explore

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DataCamp Python for MATLAB Users

Have fun!

PYTHON FOR MATLAB USERS