Functions¶

pprint.pp(object,*args,sort_dicts=False,**kwargs)¶

Prints the formatted representation ofobject followed by a newline.Ifsort_dicts is false (the default), dictionaries will be displayed withtheir keys in insertion order, otherwise the dict keys will be sorted.args andkwargs will be passed topprint() as formattingparameters.

>>>importpprint>>>stuff=['spam','eggs','lumberjack','knights','ni']>>>stuff.insert(0,stuff)>>>pprint.pp(stuff)[<Recursion on list with id=...>, 'spam', 'eggs', 'lumberjack', 'knights', 'ni']

New in version 3.8.

pprint.pprint(object,stream=None,indent=1,width=80,depth=None,*,compact=False,sort_dicts=True,underscore_numbers=False)¶

Prints the formatted representation ofobject onstream, followed by anewline. Ifstream isNone,sys.stdout is used. This may be usedin the interactive interpreter instead of theprint() function forinspecting values (you can even reassignprint=pprint.pprint for usewithin a scope).

The configuration parametersstream,indent,width,depth,compact,sort_dicts andunderscore_numbers are passed to thePrettyPrinter constructor and their meanings are asdescribed in its documentation below.

Note thatsort_dicts isTrue by default and you might want to usepp() instead where it isFalse by default.

pprint.pformat(object,indent=1,width=80,depth=None,*,compact=False,sort_dicts=True,underscore_numbers=False)¶

Return the formatted representation ofobject as a string.indent,width,depth,compact,sort_dicts andunderscore_numbers arepassed to thePrettyPrinter constructor as formatting parametersand their meanings are as described in its documentation below.

pprint.isreadable(object)¶

Determine if the formatted representation ofobject is “readable”, or can beused to reconstruct the value usingeval(). This always returnsFalsefor recursive objects.

>>>pprint.isreadable(stuff)False

pprint.isrecursive(object)¶

Determine ifobject requires a recursive representation.

pprint.saferepr(object)¶

Return a string representation ofobject, protected against recursive datastructures. If the representation ofobject exposes a recursive entry, therecursive reference will be represented as<Recursionontypenamewithid=number>. The representation is not otherwise formatted.

>>>pprint.saferepr(stuff)"[<Recursion on list with id=...>, 'spam', 'eggs', 'lumberjack', 'knights', 'ni']"

PrettyPrinter Objects¶

This module defines one class:

classpprint.PrettyPrinter(indent=1,width=80,depth=None,stream=None,*,compact=False,sort_dicts=True,underscore_numbers=False)¶

Construct aPrettyPrinter instance. This constructor understandsseveral keyword parameters.

stream (defaultsys.stdout) is afile-like object towhich the output will be written by calling itswrite() method.If bothstream andsys.stdout areNone, thenpprint() silently returns.

Other values configure the manner in which nesting of complex datastructures is displayed.

indent (default 1) specifies the amount of indentation added foreach nesting level.

depth controls the number of nesting levels which may be printed; ifthe data structure being printed is too deep, the next contained levelis replaced by.... By default, there is no constraint on thedepth of the objects being formatted.

width (default 80) specifies the desired maximum number of characters perline in the output. If a structure cannot be formatted within the widthconstraint, a best effort will be made.

compact impacts the way that long sequences (lists, tuples, sets, etc)are formatted. Ifcompact is false (the default) then each item of asequence will be formatted on a separate line. Ifcompact is true, asmany items as will fit within thewidth will be formatted on each outputline.

Ifsort_dicts is true (the default), dictionaries will be formatted withtheir keys sorted, otherwise they will display in insertion order.

Ifunderscore_numbers is true, integers will be formatted with the_ character for a thousands separator, otherwise underscores are notdisplayed (the default).

Changed in version 3.4:Added thecompact parameter.

Changed in version 3.8:Added thesort_dicts parameter.

Changed in version 3.10:Added theunderscore_numbers parameter.

Changed in version 3.11:No longer attempts to write tosys.stdout if it isNone.

>>>importpprint>>>stuff=['spam','eggs','lumberjack','knights','ni']>>>stuff.insert(0,stuff[:])>>>pp=pprint.PrettyPrinter(indent=4)>>>pp.pprint(stuff)[   ['spam', 'eggs', 'lumberjack', 'knights', 'ni'],    'spam',    'eggs',    'lumberjack',    'knights',    'ni']>>>pp=pprint.PrettyPrinter(width=41,compact=True)>>>pp.pprint(stuff)[['spam', 'eggs', 'lumberjack',  'knights', 'ni'], 'spam', 'eggs', 'lumberjack', 'knights', 'ni']>>>tup=('spam',('eggs',('lumberjack',('knights',('ni',('dead',...('parrot',('fresh fruit',))))))))>>>pp=pprint.PrettyPrinter(depth=6)>>>pp.pprint(tup)('spam', ('eggs', ('lumberjack', ('knights', ('ni', ('dead', (...)))))))

PrettyPrinter instances have the following methods:

PrettyPrinter.pformat(object)¶

Return the formatted representation ofobject. This takes into account theoptions passed to thePrettyPrinter constructor.

PrettyPrinter.pprint(object)¶

Print the formatted representation ofobject on the configured stream,followed by a newline.

The following methods provide the implementations for the correspondingfunctions of the same names. Using these methods on an instance is slightlymore efficient since newPrettyPrinter objects don’t need to becreated.

PrettyPrinter.isreadable(object)¶

Determine if the formatted representation of the object is “readable,” or can beused to reconstruct the value usingeval(). Note that this returnsFalse for recursive objects. If thedepth parameter of thePrettyPrinter is set and the object is deeper than allowed, thisreturnsFalse.

PrettyPrinter.isrecursive(object)¶

Determine if the object requires a recursive representation.

This method is provided as a hook to allow subclasses to modify the way objectsare converted to strings. The default implementation uses the internals of thesaferepr() implementation.

PrettyPrinter.format(object,context,maxlevels,level)¶

Returns three values: the formatted version ofobject as a string, a flagindicating whether the result is readable, and a flag indicating whetherrecursion was detected. The first argument is the object to be presented. Thesecond is a dictionary which contains theid() of objects that are part ofthe current presentation context (direct and indirect containers forobjectthat are affecting the presentation) as the keys; if an object needs to bepresented which is already represented incontext, the third return valueshould beTrue. Recursive calls to theformat() method should addadditional entries for containers to this dictionary. The third argument,maxlevels, gives the requested limit to recursion; this will be0 if thereis no requested limit. This argument should be passed unmodified to recursivecalls. The fourth argument,level, gives the current level; recursive callsshould be passed a value less than that of the current call.

Example¶

To demonstrate several uses of thepp() function and its parameters,let’s fetch information about a project fromPyPI:

>>>importjson>>>importpprint>>>fromurllib.requestimporturlopen>>>withurlopen('https://pypi.org/pypi/sampleproject/json')asresp:...project_info=json.load(resp)['info']

In its basic form,pp() shows the whole object:

>>>pprint.pp(project_info){'author': 'The Python Packaging Authority', 'author_email': 'pypa-dev@googlegroups.com', 'bugtrack_url': None, 'classifiers': ['Development Status :: 3 - Alpha',                 'Intended Audience :: Developers',                 'License :: OSI Approved :: MIT License',                 'Programming Language :: Python :: 2',                 'Programming Language :: Python :: 2.6',                 'Programming Language :: Python :: 2.7',                 'Programming Language :: Python :: 3',                 'Programming Language :: Python :: 3.2',                 'Programming Language :: Python :: 3.3',                 'Programming Language :: Python :: 3.4',                 'Topic :: Software Development :: Build Tools'], 'description': 'A sample Python project\n'                '=======================\n'                '\n'                'This is the description file for the project.\n'                '\n'                'The file should use UTF-8 encoding and be written using '                'ReStructured Text. It\n'                'will be used to generate the project webpage on PyPI, and '                'should be written for\n'                'that purpose.\n'                '\n'                'Typical contents for this file would include an overview of '                'the project, basic\n'                'usage examples, etc. Generally, including the project '                'changelog in here is not\n'                'a good idea, although a simple "What\'s New" section for the '                'most recent version\n'                'may be appropriate.', 'description_content_type': None, 'docs_url': None, 'download_url': 'UNKNOWN', 'downloads': {'last_day': -1, 'last_month': -1, 'last_week': -1}, 'home_page': 'https://github.com/pypa/sampleproject', 'keywords': 'sample setuptools development', 'license': 'MIT', 'maintainer': None, 'maintainer_email': None, 'name': 'sampleproject', 'package_url': 'https://pypi.org/project/sampleproject/', 'platform': 'UNKNOWN', 'project_url': 'https://pypi.org/project/sampleproject/', 'project_urls': {'Download': 'UNKNOWN',                  'Homepage': 'https://github.com/pypa/sampleproject'}, 'release_url': 'https://pypi.org/project/sampleproject/1.2.0/', 'requires_dist': None, 'requires_python': None, 'summary': 'A sample Python project', 'version': '1.2.0'}

The result can be limited to a certaindepth (ellipsis is used for deepercontents):

>>>pprint.pp(project_info,depth=1){'author': 'The Python Packaging Authority', 'author_email': 'pypa-dev@googlegroups.com', 'bugtrack_url': None, 'classifiers': [...], 'description': 'A sample Python project\n'                '=======================\n'                '\n'                'This is the description file for the project.\n'                '\n'                'The file should use UTF-8 encoding and be written using '                'ReStructured Text. It\n'                'will be used to generate the project webpage on PyPI, and '                'should be written for\n'                'that purpose.\n'                '\n'                'Typical contents for this file would include an overview of '                'the project, basic\n'                'usage examples, etc. Generally, including the project '                'changelog in here is not\n'                'a good idea, although a simple "What\'s New" section for the '                'most recent version\n'                'may be appropriate.', 'description_content_type': None, 'docs_url': None, 'download_url': 'UNKNOWN', 'downloads': {...}, 'home_page': 'https://github.com/pypa/sampleproject', 'keywords': 'sample setuptools development', 'license': 'MIT', 'maintainer': None, 'maintainer_email': None, 'name': 'sampleproject', 'package_url': 'https://pypi.org/project/sampleproject/', 'platform': 'UNKNOWN', 'project_url': 'https://pypi.org/project/sampleproject/', 'project_urls': {...}, 'release_url': 'https://pypi.org/project/sampleproject/1.2.0/', 'requires_dist': None, 'requires_python': None, 'summary': 'A sample Python project', 'version': '1.2.0'}

Additionally, maximum characterwidth can be suggested. If a long objectcannot be split, the specified width will be exceeded:

>>>pprint.pp(project_info,depth=1,width=60){'author': 'The Python Packaging Authority', 'author_email': 'pypa-dev@googlegroups.com', 'bugtrack_url': None, 'classifiers': [...], 'description': 'A sample Python project\n'                '=======================\n'                '\n'                'This is the description file for the '                'project.\n'                '\n'                'The file should use UTF-8 encoding and be '                'written using ReStructured Text. It\n'                'will be used to generate the project '                'webpage on PyPI, and should be written '                'for\n'                'that purpose.\n'                '\n'                'Typical contents for this file would '                'include an overview of the project, '                'basic\n'                'usage examples, etc. Generally, including '                'the project changelog in here is not\n'                'a good idea, although a simple "What\'s '                'New" section for the most recent version\n'                'may be appropriate.', 'description_content_type': None, 'docs_url': None, 'download_url': 'UNKNOWN', 'downloads': {...}, 'home_page': 'https://github.com/pypa/sampleproject', 'keywords': 'sample setuptools development', 'license': 'MIT', 'maintainer': None, 'maintainer_email': None, 'name': 'sampleproject', 'package_url': 'https://pypi.org/project/sampleproject/', 'platform': 'UNKNOWN', 'project_url': 'https://pypi.org/project/sampleproject/', 'project_urls': {...}, 'release_url': 'https://pypi.org/project/sampleproject/1.2.0/', 'requires_dist': None, 'requires_python': None, 'summary': 'A sample Python project', 'version': '1.2.0'}