Work with Long Strings in Python

This article discusses different ways to write long strings in Python.

Long String in One Line¶

A long string can be put on the the same line, which is ugly of course.

long_string = "This is a very looooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong string."
print(long_string)

This is a very looooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooong string.

Concatenate Multiple Strings Using `+`¶

Use + to concatenate multiple string, which is is visually good but not recommended (due to simpler alternatives).

long_string = "This is a very" + "loooooooooooooooooooooooooooooooooooong string."
print(long_string)

This is a veryloooooooooooooooooooooooooooooooooooong string.

Parentheses¶

Parentheses can be used to break a long string into multiple lines and avoid the side effect of white spaces at the same time.

long_string = "This is a very looooooooooooooooooooooooooooooooooooong string."
print(long_string)

This is a very looooooooooooooooooooooooooooooooooooong string.

This is especially convenient if the long string is passed directly to a method.

len("This is a very looooooooooooooooooooooooooooooooooooong string.")

63

Line Continuation `\`¶

The line continuation symbol \ can be used to break a string into multiple lines. This is another good alternative if you do not like the parentheses way.

long_string = "This is a very looooooooooooooooooooooooooooooooooong string."
print(long_string)

This is a very looooooooooooooooooooooooooooooooooong string.

Triple Quotes¶

Triple double/single quotes is a very convenient way to write a large chunk of string in Python. Howeve, whites spaces are kept literally in a triple-qutoe string, which might or might not be what you want.

long_string = """This is a very
    loooooooooooooooooooooooooooooooooooooong string.
    """
print(long_string)

This is a very
    loooooooooooooooooooooooooooooooooooooong string.

Fortunately, there are a few functions in Python which can easily remove leading whites spaces in each line of a tripple quotes string.

inspect.cleandoc¶

import inspect

s = """
    if [[ -f ... ]]; then
        echo
    fi
    """

print(inspect.cleandoc(s))

if [[ -f ... ]]; then
    echo
fi

textwrap.dedent¶

import textwrap

s = """\
    if [[ -f ... ]]; then
        echo
    fi
    """

print(textwrap.dedent(s))

if [[ -f ... ]]; then
    echo
fi

References¶

https://docs.python.org/3/library/stdtypes.html#textseq