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This article mainly explains "how to use the pprint module in Python". Interested friends may wish to have a look. The method introduced in this paper is simple, fast and practical. Now let the editor take you to learn how to use the pprint module in Python.

one。 Pprint Aesthetic Printing data structure

The pprint module contains a "beauty printer" to generate a beautiful view of the data structure. Formatting tools generate representations of data structures that can not only be correctly parsed by the interpreter, but also easy for people to read. The output is placed on one line as much as possible and is indented when it is broken down into multiple lines.

1. Print from pprint import pprintdata = [(1, {'axie:' aforementioned, 'baked:' baked, 'cached:' cased: 'caged,' dashed:'D'}), (2, {'eyed:' estranged, 'favored:' faded, 'grubbed:' gay, 'hacked:' hacked, 'ified:' Izzy, 'jaded:' J'') ), (3, ['masked,' n']), (4, ['oiled,' paired,'q']), (5, ['ringing,' sounding, 'tasking,' vying, 'xylene,' yearly,'z'])) ] print ('PRINT:') print (data) print () print (' PPRINT:') pprint (data)

Pprint () formats an object and passes it as an argument to a data stream (or the default sys.stdout).

PRINT: [(1, {'adept:' aforementioned, 'baked:' baked, 'cached:' cached, 'dashed:' D'}), (2, {'eyed:' estranged, 'favored:' faded, 'grubbed:' gay, 'hacked:' hacked, 'ified:' irrelevant, 'jacked:' jacked, 'kicking:' K' K') ), (3, ['masked,' n']), (4, ['oiled,' paired,'Q']), (5, ['ritual,' tu',', 'PPRINT: [(1, {' axie: 'Aging,' baked: 'baked,' cased:'C'])] ), (2, {'eyed:' estranged, 'favored:' favored, 'gaded:' Globe, 'hacked:' Haven, 'iTunes:' Illustrated, 'jaded:' jaded, 'Kwon:' Kwon, 'lumped:' L'}), (3, ['masked,' n']), (4) ['ostatic,' paired,'Q']), (5, ['ringing,' tu',','x','y','z'])] 2. Formatting

To format a data structure instead of writing it directly to a stream (that is, for logging), you can use pformat () to build a string representation.

Import loggingfrom pprint import pformatdata = [(1, {'adept:' aforementioned, 'baked:' baked, 'caged:' cached, 'dashed:' D'}), (2, {'eyed:' estranged, 'favored:' faded, 'gelled:' gay, 'hacked:' hacked, 'ified:' irrelevant, 'jaded:' J') ), (3, ['masked,' n']), (4, ['oiled,' paired,'q']), (5, ['ringing,' sounding, 'tasking upright,' vested,'x', 'yearly,' z']),] logging.basicConfig (level=logging.DEBUG) Format='% (levelname)-8s% (message) slots,) logging.debug ('Logging pformatted data') formatted = pformat (data) for line in formatted.splitlines (): logging.debug (line.rstrip ())

You can then print the formatted string separately or log it.

DEBUG Logging pformatted dataDEBUG [(1, {'adept:' abug, 'baked:' compressed, 'cached:' Cilled, 'dashed:' D'}), DEBUG (2), DEBUG (2), (2) penciled debug {'eforth:' eyed: 'feathered dabug' favored: 'favored dabug' favored: 'Globe legendary Debug' hitch: 'haug:' I'' DEBUG 'jacks:' Jacks dongles: 'Knights dagger:' L'}), DEBUG (3, ['masks,' n']), DEBUG (4, ['oaths,' packs,'Q']), DEBUG (5, ['ringing,' slots, 'tu',' vaults, 'xylene,' yudes,'z'])] 3. Arbitrary class

If a custom class defines a _ _ repr__ () method, the PrettyPrinter class used by pprint () can also handle such a custom class.

From pprint import pprintclass node: def _ init__ (self, name, contents= []): self.name = name self.contents = contents [:] def _ repr__ (self): return ('node (' + repr (self.name) +','+ repr (self.contents) +') trees = [node ('node-1') Node ('node-2', [node (' node-2-1')]), node ('node-3', [node (' node-3-1')]),] pprint (trees)

Returns a complete string representation using the representation of nested objects combined by PrettyPrinter.

[node ('node-1', []), node (' node-2', [node ('node-1, [])]), node (' node-3', [node ('node-3-1), [])] 4. Recursion

The recursive data structure is represented by a reference to the original data source in the form of

From pprint import pprintlocal_data = ['id, 'baked, 1,2] local_data.append (local_data) print (' id (local_data) = >', id (local_data)) pprint (local_data)

In this example, the list local_data is added to itself, which creates a recursive reference.

Id (local_data) = > 2763816527488 ['await,' baked, 1,2,] 5. Limit nested output

For very deep data structures, the output may not be required to contain all the details. The data may not be properly formatted, the formatted text may be too large to manage, or some data may be redundant.

From pprint import pprintdata = [(1, {'adept:' aforementioned, 'baked:' baked, 'caged:' cached, 'dashed:' D'}), (2, {'eyed:' estranged, 'favored:' faded, 'gelled:' gay, 'hacked:' hacked, 'ified:' irrelevant, 'jaded:' J') ), (3, ['masked,' n']), (4, ['oiled,' paired,'q']), (5, [data, depth=1) pprint (data depth=2)

Use the depth parameter to control the depth at which beauty printers recursively process nested data structures. Levels that are not included in the output are indicated by ellipses.

[(...), (...)] [(1, {.}), (2, {.}), (3, [.]), (4, [.]), (5, [])] 6. Control output width

The default output width of formatted text is 80 columns. To adjust this width, you can use the parameter width in pprint ().

From pprint import pprintdata = [(1, {'adept:' aforementioned, 'baked:' baked, 'caged:' cached, 'dashed:' D'}), (2, {'eyed:' estranged, 'favored:' faded, 'gelled:' gay, 'hacked:' hacked, 'ified:' irrelevant, 'jaded:' J') ), (3, ['masked,' n']), (4, ['oiled,' paired,'q']), (5, ['ringing,' sounding, 'tasking upright,' vested,'x', 'yearly,' z']),] for width in [80,5]: print ('WIDTH =') Width) pprint (data, width=width) print ()

When the width is too small to satisfy the formatted data structure, if truncation or line change will result in illegal syntax, then it will not be truncated or changed.

WIDTH = 80 [(1, {'axie:' aforementioned, 'baked:' baked, 'cached:' caged, 'dashed:' D'}), (2, {'eyed:' estranged, 'favored:' faded, 'galled:' gay, 'hagged:' hacked, 'ified:' Illustrated, 'jacked:' jacked, 'Kwon:' K' K') ), (3, ['masked,' n']), (4, ['oiled,' paired,'Q']), (5, ['ritual,' tu',', 'WIDTH','x','y','z'])] WIDTH = 5 [(1, {'axie:' Agar, 'baked:' B'') ), (2, {'eyed:' estranged, 'faded:' favored, 'galled:' Globe, 'hacked:' hacked, 'ified:' Izzy, 'jaded:' Jacks, 'kills:' Knights, 'lags:' L'}), (3, [`m'') 'n']), (4, [' oiled, 'paired,' Q']), (5, ['ringing,' tu',','x','y','z'])]

The compact flag tells pprint () to try to put more data on each row instead of breaking the complex data structure into multiple rows.

From pprint import pprintdata = [(1, {'adept:' aforementioned, 'baked:' baked, 'caged:' cached, 'dashed:' D'}), (2, {'eyed:' estranged, 'favored:' faded, 'gelled:' gay, 'hacked:' hacked, 'ified:' irrelevant, 'jaded:' J') ), (3, ['masked,' n']), (4, ['oiled,' paired,'q']), (5, ['ringing,' sounding, 'tasking upright,' vested,'x', 'yearly,' z']),] for width in [80,5]: print ('WIDTH =') Width) pprint (data, width=width) print ()

This example shows that a data structure breaks down when it cannot fit on a row (the same is true of the second item in the data list). If multiple elements can be placed on one line (such as the third and fourth members), they will be placed on the same line.

WIDTH = 80 [(1, {'axie:' aforementioned, 'baked:' baked, 'cached:' caged, 'dashed:' D'}), (2, {'eyed:' estranged, 'favored:' faded, 'galled:' gay, 'hagged:' hacked, 'ified:' Illustrated, 'jacked:' jacked, 'Kwon:' K' K') ), (3, ['masked,' n']), (4, ['oiled,' paired,'Q']), (5, ['ritual,' tu',', 'WIDTH','x','y','z'])] WIDTH = 5 [(1, {'axie:' Agar, 'baked:' B'') ), (2, {'eyed:' estranged, 'faded:' favored, 'galled:' Globe, 'hacked:' hacked, 'ified:' Izzy, 'jaded:' Jacks, 'kills:' Knights, 'lags:' L'}), (3, [`m'') 'n']), (4, ['oiled,' paired,'Q']), (5, ['ringing,' tu',','x','y','z'])] I believe you have a deeper understanding of "how to use the pprint module in Python", so you might as well do it in practice. Here is the website, more related content can enter the relevant channels to inquire, follow us, continue to learn!

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