Getting to know glue IN TERMEDIATE REGULAR EX P RES S ION S IN R - - PowerPoint PPT Presentation

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Apr 19, 2023 376 likes •582 views

Getting to know glue IN TERMEDIATE REGULAR EX P RES S ION S IN R Angelo Zehr Instructor Pasting is tedious username <- "Adam" paste("Hi", username) Will print: Hi Adam library("glue") username <-

SLIDE 1

Getting to know glue

IN TERMEDIATE REGULAR EX P RES S ION S IN R

Angelo Zehr

Instructor

SLIDE 2

INTERMEDIATE REGULAR EXPRESSIONS IN R

Pasting is tedious

username <- "Adam" paste("Hi", username)

Will print: Hi Adam

library("glue") username <- "Adam" glue("Hi {username}")

Will also print: Hi Adam

SLIDE 3

INTERMEDIATE REGULAR EXPRESSIONS IN R

What you pass to glue

username_1 <- "Adam" username_2 <- NA glue( "Hi {username_1} and {username_2}", .na = "" )

Will print: Hi Adam and

SLIDE 4

INTERMEDIATE REGULAR EXPRESSIONS IN R

What is a template string?

username_1 <- "Adam" username_2 <- "Eve" glue("Hi {username_1} and {username_2}")

Will print: Hi Adam and Eve

glue("{2 + 2}") will print "4"

SLIDE 5

INTERMEDIATE REGULAR EXPRESSIONS IN R

Temporary variables

glue( "The train is {length} meters long.", length = 50 )

Will print:

"The train is 50 meters long."

SLIDE 6

INTERMEDIATE REGULAR EXPRESSIONS IN R

Glue inside data frames

df %>% mutate( new_column = glue("Hi {username}") )

Will return:

username new_column 1 "Adam" "Hi Adam"

SLIDE 7

Let's practice!

IN TERMEDIATE REGULAR EX P RES S ION S IN R

SLIDE 8

Collapsing multiple elements into a string

IN TERMEDIATE REGULAR EX P RES S ION S IN R

Angelo Zehr

Data Journalist

SLIDE 9

INTERMEDIATE REGULAR EXPRESSIONS IN R

Introducing glue_collapse

usernames <- c("Adam", "Betty", "Cora", "David") glue_collapse(usernames)

Will print AdamBettyCoraDavid

SLIDE 10

INTERMEDIATE REGULAR EXPRESSIONS IN R

More elaborate example

glue_collapse( usernames, sep = ", ", last = ", and ", width = 27 )

Will print Adam, Betty, Cora, and Dav...

SLIDE 11

INTERMEDIATE REGULAR EXPRESSIONS IN R

Passing glue collapse to glue

glue( "Hello {users}.", users = glue_collapse( usernames, sep = ", ", last = ", and " ) )

Will print Hello Adam, Betty, Cora, and David.

SLIDE 12

INTERMEDIATE REGULAR EXPRESSIONS IN R

Collapsing columns of a data frame

Data frame df

x y 1 4 2 5 3 6 glue_collapse(df$x) will print 123

SLIDE 13

Let's practice!

IN TERMEDIATE REGULAR EX P RES S ION S IN R

SLIDE 14

Gluing regular expressions

IN TERMEDIATE REGULAR EX P RES S ION S IN R

Angelo Zehr

Data Journalist

SLIDE 15

INTERMEDIATE REGULAR EXPRESSIONS IN R

Collapsing with the pipe

pattern = "Nemo|Harmony|Dory"

can also be created like this:

names <- c("Nemo", "Harmony", "Dory") pattern = glue_collapse(names, sep = "|")

SLIDE 16

INTERMEDIATE REGULAR EXPRESSIONS IN R

A quick refresh

Character Class Name Example

\\d

Digit

0, 1, 2, 3,… \\w

Word

a, b, c…, 1, 2, 3…, _ \\s

Space

" " , tabs and line breaks [A-Za-z]

Letter

A, B, C,…, a, b, c,…

SLIDE 17

INTERMEDIATE REGULAR EXPRESSIONS IN R

A quick refresh

Multiplier Repetitions

One or more repetitions

Zero or more repetitions

SLIDE 18

INTERMEDIATE REGULAR EXPRESSIONS IN R

Break up complex patterns

api_response <- "payload: 'Adam, 5, 3', headers: 'Auth...'" str_match(api_resopnse, pattern = "[A-Za-z]+, \\d+, \\d+")

Will match: Adam, 5, 3

pattern = glue_collapse(c( "name" = "[A-Za-z]+", ", ", "attempts" = "\\d+", ", ", "logins" = "\\d+" ))

SLIDE 19

Let's practice!

IN TERMEDIATE REGULAR EX P RES S ION S IN R