Fall 2024 - P4

Big Idea 3 .1
.1.1 Python Variables .1.2 Python Data Types .1.3 JavaScript Variables .1.4 JavaScript Data Types
.4
.4.1 Strings .4.2 Strings and Functions .4.3 JavaScript Strings .4.4 Strings Hacks

Lesson 4.2 Strings and Functions

• • 1 min read

String Functions In Python

  • more functions you can do on strings
tiger_fact = "the stripes on a Tiger are unique, similar to the human fingerprint"


#make everything lowercase or uppercase, use .lower() or .upper()
print(tiger_fact.lower())
print(tiger_fact.upper())

the stripes on a tiger are unique, similar to the human fingerprint
THE STRIPES ON A TIGER ARE UNIQUE, SIMILAR TO THE HUMAN FINGERPRINT

#count how many times an argument appears
#don't forget quotes
print(tiger_fact.count("the"))

2

#find a specific index
#index is the number of a character in a string
print(tiger_fact.find("unique"))
#27 means the letter "u" is the 27th character

27

#replace something in a string, there are 2 parts

#format: variable.replace('thing you want replaced', 'replacement')
tiger_fact.replace('Tiger', 'zebra')
#this will not work on it's own. To make it work, there are 2 options:

#option1: make new var 
new_tiger_fact = tiger_fact.replace('Tiger', 'zebra')
print(new_tiger_fact)

#option2: replace old var with new var
tiger_fact = tiger_fact.replace('Tiger', 'zebra')
print(tiger_fact)

the stripes on a zebra are unique, similar to the human fingerprint
the stripes on a zebra are unique, similar to the human fingerprint

Concat

  • stands for concatinate
  • join multiple variables together
fish = "fish"
fish1 = "angel"
fish2 = "cat"
fish3 = "puffer"


bad_format_species = fish1 + fish + fish2 + fish + fish3 + fish
print(bad_format_species)
#you can also do this directly under print instead of making a new var

#to better format these fishes, add commas and spaces as separate strings in variable
good_format_species = fish1 + fish + ', ' + fish2 + fish + ', ' + fish3 + fish
print(good_format_species)

angelfishcatfishpufferfish
angelfish, catfish, pufferfish
Formatted string basics
  • when you are concating a lot of variables, using plus signs and individual strings for spaces gets messy
  • formatted strings make it easier to read and keep track of everything
  • use placeholders {} then replace them later on with .format()
better_format_species = '{}{}, {}{}, and {}{} are my favorite fish!' .format(fish1,fish,fish2,fish,fish3,fish)
print(better_format_species)

angelfish, catfish, and pufferfish, are my favorite fish!