New in version 2.3.
The textwrap module provides two convenience functions, wrap() and fill(), as well as TextWrapper, the class that does all the work, and a utility function dedent(). If you’re just wrapping or filling one or two text strings, the convenience functions should be good enough; otherwise, you should use an instance of TextWrapper for efficiency.
Wraps the single paragraph in text (a string) so every line is at most width characters long. Returns a list of output lines, without final newlines.
Optional keyword arguments correspond to the instance attributes of TextWrapper, documented below. width defaults to 70.
Wraps the single paragraph in text, and returns a single string containing the wrapped paragraph. fill() is shorthand for
Both wrap() and fill() work by creating a TextWrapper instance and calling a single method on it. That instance is not reused, so for applications that wrap/fill many text strings, it will be more efficient for you to create your own TextWrapper object.
Text is preferably wrapped on whitespaces and right after the hyphens in hyphenated words; only then will long words be broken if necessary, unless TextWrapper.break_long_words is set to false.
An additional utility function, dedent(), is provided to remove indentation from strings that have unwanted whitespace to the left of the text.
Remove any common leading whitespace from every line in text.
This can be used to make triple-quoted strings line up with the left edge of the display, while still presenting them in the source code in indented form.
Note that tabs and spaces are both treated as whitespace, but they are not equal: the lines " hello" and "\thello" are considered to have no common leading whitespace. (This behaviour is new in Python 2.5; older versions of this module incorrectly expanded tabs before searching for common leading whitespace.)
def test(): # end first line with \ to avoid the empty line! s = '''\ hello world ''' print repr(s) # prints ' hello\n world\n ' print repr(dedent(s)) # prints 'hello\n world\n'
The TextWrapper constructor accepts a number of optional keyword arguments. Each argument corresponds to one instance attribute, so for example
wrapper = TextWrapper(initial_indent="* ")
is the same as
wrapper = TextWrapper() wrapper.initial_indent = "* "
You can re-use the same TextWrapper object many times, and you can change any of its options through direct assignment to instance attributes between uses.
The TextWrapper instance attributes (and keyword arguments to the constructor) are as follows:
(default: True) If true, each whitespace character (as defined by string.whitespace) remaining after tab expansion will be replaced by a single space.
(default: True) If true, whitespace that, after wrapping, happens to end up at the beginning or end of a line is dropped (leading whitespace in the first line is always preserved, though).
New in version 2.6: Whitespace was always dropped in earlier versions.
(default: False) If true, TextWrapper attempts to detect sentence endings and ensure that sentences are always separated by exactly two spaces. This is generally desired for text in a monospaced font. However, the sentence detection algorithm is imperfect: it assumes that a sentence ending consists of a lowercase letter followed by one of '.', '!', or '?', possibly followed by one of '"' or "'", followed by a space. One problem with this is algorithm is that it is unable to detect the difference between “Dr.” in
[...] Dr. Frankenstein's monster [...]
and “Spot.” in
[...] See Spot. See Spot run [...]
fix_sentence_endings is false by default.
Since the sentence detection algorithm relies on string.lowercase for the definition of “lowercase letter,” and a convention of using two spaces after a period to separate sentences on the same line, it is specific to English-language texts.
(default: True) If true, wrapping will occur preferably on whitespaces and right after hyphens in compound words, as it is customary in English. If false, only whitespaces will be considered as potentially good places for line breaks, but you need to set break_long_words to false if you want truly insecable words. Default behaviour in previous versions was to always allow breaking hyphenated words.
New in version 2.6.
TextWrapper also provides two public methods, analogous to the module-level convenience functions: