Strings

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

python
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

python
a = "Hello"
print(a)

### Hello

Multi-line strings

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

python
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:

python
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:

python
for x in "banana":
    print(x)

Length

len() returns the number of characters:

python
a = "Hello, World!"
print(len(a))

### 13

Check for a word

Use in and not in to test whether text appears:

python
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.