Lesson 17 +10 XP

Strings

Strings

Strings are text. In Python, a string is surrounded by single or double quotes.

print("Hello")     # double quotes
print('Hello')     # single quotes

Quotes inside strings

  • Use double quotes if your text contains a single quote: "It's fine".
  • Use single quotes if your text contains a double quote: 'She said "hi"'.

Assign a string to a variable

a = "Hello"
print(a)  # Hello

Multi-line strings

Use three quotes (single or double) for text that spans several lines:

a = """One line.
Two lines.
Three lines."""
print(a)

Strings are arrays of characters

Python has no char type. A single character is just a string of length 1. You can grab one with square brackets:

a = "Hello, World!"
print(a[1])  # e

Remember: counting starts at 0, so a[0] is the first character.

Loop through a string

A for loop visits each character:

for x in "banana":
    print(x)

Length

len() returns the number of characters:

a = "Hello, World!"
print(len(a))  # 13

Check for a word

Use in and not in to test whether text appears:

txt = "The best things in life are free!"
print("free" in txt)    # True
print("free" not in txt)# False

TL;DR

  • Strings use single or double quotes; be flexible with quotes inside.
  • Triple quotes make multi-line strings.
  • s[0] is the first character (0-indexed).
  • len() gives length; in checks for text.