String Methods

String Methods

Strings come with a rich toolbox of methods. Here are the ones you'll use most.

Case and spacing

s = "  Hello World  "
s.upper()          # '  HELLO WORLD  '
s.lower()          # '  hello world  '
s.strip()          # 'Hello World'
s.capitalize()     # '  Hello world  '
s.title()          # '  Hello World  '
s.swapcase()       # '  hELLO wORLD  '

Search and replace

s = "Hello, World!"
s.find("World")   # 7
s.index("World")  # 7
s.count("o")      # 2
s.replace("World", "Python")  # 'Hello, Python!'
s.startswith("He")  # True
s.endswith("!")     # True

Checks (return True or False)

s = "123"
s.isalnum()   # True (letters or digits)
s.isalpha()   # False (digits are not letters)
s.isdigit()   # True
s.islower()   # False
s.isupper()   # False
s.isspace()   # False

Split and join

"a,b,c".split(",")   # ['a', 'b', 'c']
"-".join(["a", "b"]) # 'a-b'

Padding and centering

"42".zfill(5)    # '00042'
"hi".center(6)   # '  hi  '

Remember

Methods return new strings. The original is never modified.

TL;DR

• Case: upper, lower, capitalize, title, swapcase.
• Search: find, index, count, startswith, endswith, replace.
• Checks: isalnum, isalpha, isdigit, islower, isupper.
• Tools: split, join, zfill, center, strip.