Strings in Python

In Python, strings are sequences of characters enclosed in either single (') or double (") quotation marks. Both are treated the same.

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print("Hello")
print('Hello')

Quotes Inside Strings

You can use quotes inside a string as long as they do not match the surrounding quotes:

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print("It's alright")         # Single quote inside double quotes
print('He is called "Johnny"') # Double quote inside single quotes

Python Assign String Variables

You can assign a string to a variable by using the equal sign (=):

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a = "Hello"
print(a)

Python multiline strings

To assign a multiline string, use three single (''') or double quotes ("""):

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a = """Lorem ipsum dolor sit amet,
consectetur adipiscing elit,
sed do eiusmod tempor incididunt
ut labore et dolore magna aliqua."""
print(a)

b = '''Lorem ipsum dolor sit amet,
consectetur adipiscing elit.'''
print(b)

The line breaks are preserved in the output.

Python String Length

To get the length of a string, use the len() function:

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

Check if a Substring is Present

Use the in keyword to check if a substring exists within a string:

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txt = "The best things in life are free!"
print("free" in txt)  # Output: True

Check if NOT Present

To check if a substring is not present, use the not in keyword:

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

Python Slicing Strings

You can slice a string by specifying a start and an end index, separated by a colon:

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b = "Hello, World!"
print(b[2:5])  # Output: 'llo'

• Slice from the start: Omit the start index to begin at the first character.

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print(b[:5])  # Output: 'Hello'

• Slice to the end: Omit the end index to go to the end of the string.

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print(b[2:])  # Output: 'llo, World!'

• Negative indexing: Use negative numbers to start slicing from the end of the string.

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print(b[-5:-2])  # Output: 'orl'