Everything You Need to Know About Python Strings

What is a string?

In plain English, a string is a block of text. More technically, it is a sequence of letters, numbers, and Unicode characters—and it is a built-in data type in Python.

Creating a string

To create a string in Python, define it inside double or single quotes:

"Something like this"
'This works too'

Storing a string in a variable

# The quotation marks are different, but these are both strings.
some_variable_name = "Hey, this is a Python string"

# Or:
some_variable_name = 'Hey, look—a single-quote string'

Indexing

You can get a character from any string using its index. Python starts counting at zero, so the first letter is at index 0:

text = 'hey look a single quote string'

print(text[0]) # -> h
print(text[1]) # -> e
print(text[2]) # -> y

Reverse indexing

You can also read values from the end of the string. Use -1 to get the last character, -2 for the second-to-last character, and so on:

text = 'hey look a single quote string'

print(text[-1]) # -> g
print(text[-2]) # -> n
print(text[-3]) # -> i

Getting multiple characters

To get a subset of text, specify the starting and ending indexes. The ending index is not included in the result:

text = 'whilelab'

print(text[0:5]) # -> while
print(text[3:6]) # -> lel

# Negative indexing can exclude characters from the end.
print(text[0:-3]) # -> while

Connecting two strings

Use the + operator to concatenate strings:

text = 'Python tutorials on '
text_2 = 'YouTube'

full_sentence = text + text_2
print(full_sentence) # -> Python tutorials on YouTube

Multiplying a string by a number

Multiplication repeats a string:

greetings = 'Hey!'
repeated_greetings = greetings * 3
print(repeated_greetings) # -> Hey!Hey!Hey!

Getting the length of a string

Python has a built-in len() function that returns the length of a sequence, including a string:

sentence = 'Everything'
len(sentence) # -> 10

Checking whether text appears in a string

Use the built-in in keyword to check whether a string is part of another string:

text = "Sun is directly above Earth's equator"
print('directly' in text) # -> True

print('moon' in text) # -> False

print('sun' in text) # -> False, because the check is case-sensitive

print('ab' in text) # -> True; it matches the 'ab' in 'above'

These basics—creation, indexing, slicing, concatenation, repetition, length checks, and membership checks—cover the operations you will use constantly when working with text in Python.