projektAI/venv/Lib/site-packages/sklearn/utils/_pprint.py
2021-06-06 22:13:05 +02:00

448 lines
18 KiB
Python

"""This module contains the _EstimatorPrettyPrinter class used in
BaseEstimator.__repr__ for pretty-printing estimators"""
# Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
# 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018 Python Software Foundation;
# All Rights Reserved
# Authors: Fred L. Drake, Jr. <fdrake@acm.org> (built-in CPython pprint module)
# Nicolas Hug (scikit-learn specific changes)
# License: PSF License version 2 (see below)
# PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2
# --------------------------------------------
# 1. This LICENSE AGREEMENT is between the Python Software Foundation ("PSF"),
# and the Individual or Organization ("Licensee") accessing and otherwise
# using this software ("Python") in source or binary form and its associated
# documentation.
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# PYTHON WILL NOT INFRINGE ANY THIRD PARTY RIGHTS.
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# 8. By copying, installing or otherwise using Python, Licensee agrees to be
# bound by the terms and conditions of this License Agreement.
# Brief summary of changes to original code:
# - "compact" parameter is supported for dicts, not just lists or tuples
# - estimators have a custom handler, they're not just treated as objects
# - long sequences (lists, tuples, dict items) with more than N elements are
# shortened using ellipsis (', ...') at the end.
import inspect
import pprint
from collections import OrderedDict
from ..base import BaseEstimator
from .._config import get_config
from . import is_scalar_nan
class KeyValTuple(tuple):
"""Dummy class for correctly rendering key-value tuples from dicts."""
def __repr__(self):
# needed for _dispatch[tuple.__repr__] not to be overridden
return super().__repr__()
class KeyValTupleParam(KeyValTuple):
"""Dummy class for correctly rendering key-value tuples from parameters."""
pass
def _changed_params(estimator):
"""Return dict (param_name: value) of parameters that were given to
estimator with non-default values."""
params = estimator.get_params(deep=False)
init_func = getattr(estimator.__init__, 'deprecated_original',
estimator.__init__)
init_params = inspect.signature(init_func).parameters
init_params = {name: param.default for name, param in init_params.items()}
def has_changed(k, v):
if k not in init_params: # happens if k is part of a **kwargs
return True
if init_params[k] == inspect._empty: # k has no default value
return True
# try to avoid calling repr on nested estimators
if (isinstance(v, BaseEstimator) and
v.__class__ != init_params[k].__class__):
return True
# Use repr as a last resort. It may be expensive.
if (repr(v) != repr(init_params[k]) and
not (is_scalar_nan(init_params[k]) and is_scalar_nan(v))):
return True
return False
return {k: v for k, v in params.items() if has_changed(k, v)}
class _EstimatorPrettyPrinter(pprint.PrettyPrinter):
"""Pretty Printer class for estimator objects.
This extends the pprint.PrettyPrinter class, because:
- we need estimators to be printed with their parameters, e.g.
Estimator(param1=value1, ...) which is not supported by default.
- the 'compact' parameter of PrettyPrinter is ignored for dicts, which
may lead to very long representations that we want to avoid.
Quick overview of pprint.PrettyPrinter (see also
https://stackoverflow.com/questions/49565047/pprint-with-hex-numbers):
- the entry point is the _format() method which calls format() (overridden
here)
- format() directly calls _safe_repr() for a first try at rendering the
object
- _safe_repr formats the whole object reccursively, only calling itself,
not caring about line length or anything
- back to _format(), if the output string is too long, _format() then calls
the appropriate _pprint_TYPE() method (e.g. _pprint_list()) depending on
the type of the object. This where the line length and the compact
parameters are taken into account.
- those _pprint_TYPE() methods will internally use the format() method for
rendering the nested objects of an object (e.g. the elements of a list)
In the end, everything has to be implemented twice: in _safe_repr and in
the custom _pprint_TYPE methods. Unfortunately PrettyPrinter is really not
straightforward to extend (especially when we want a compact output), so
the code is a bit convoluted.
This class overrides:
- format() to support the changed_only parameter
- _safe_repr to support printing of estimators (for when they fit on a
single line)
- _format_dict_items so that dict are correctly 'compacted'
- _format_items so that ellipsis is used on long lists and tuples
When estimators cannot be printed on a single line, the builtin _format()
will call _pprint_estimator() because it was registered to do so (see
_dispatch[BaseEstimator.__repr__] = _pprint_estimator).
both _format_dict_items() and _pprint_estimator() use the
_format_params_or_dict_items() method that will format parameters and
key-value pairs respecting the compact parameter. This method needs another
subroutine _pprint_key_val_tuple() used when a parameter or a key-value
pair is too long to fit on a single line. This subroutine is called in
_format() and is registered as well in the _dispatch dict (just like
_pprint_estimator). We had to create the two classes KeyValTuple and
KeyValTupleParam for this.
"""
def __init__(self, indent=1, width=80, depth=None, stream=None, *,
compact=False, indent_at_name=True,
n_max_elements_to_show=None):
super().__init__(indent, width, depth, stream, compact=compact)
self._indent_at_name = indent_at_name
if self._indent_at_name:
self._indent_per_level = 1 # ignore indent param
self._changed_only = get_config()['print_changed_only']
# Max number of elements in a list, dict, tuple until we start using
# ellipsis. This also affects the number of arguments of an estimators
# (they are treated as dicts)
self.n_max_elements_to_show = n_max_elements_to_show
def format(self, object, context, maxlevels, level):
return _safe_repr(object, context, maxlevels, level,
changed_only=self._changed_only)
def _pprint_estimator(self, object, stream, indent, allowance, context,
level):
stream.write(object.__class__.__name__ + '(')
if self._indent_at_name:
indent += len(object.__class__.__name__)
if self._changed_only:
params = _changed_params(object)
else:
params = object.get_params(deep=False)
params = OrderedDict((name, val)
for (name, val) in sorted(params.items()))
self._format_params(params.items(), stream, indent, allowance + 1,
context, level)
stream.write(')')
def _format_dict_items(self, items, stream, indent, allowance, context,
level):
return self._format_params_or_dict_items(
items, stream, indent, allowance, context, level, is_dict=True)
def _format_params(self, items, stream, indent, allowance, context, level):
return self._format_params_or_dict_items(
items, stream, indent, allowance, context, level, is_dict=False)
def _format_params_or_dict_items(self, object, stream, indent, allowance,
context, level, is_dict):
"""Format dict items or parameters respecting the compact=True
parameter. For some reason, the builtin rendering of dict items doesn't
respect compact=True and will use one line per key-value if all cannot
fit in a single line.
Dict items will be rendered as <'key': value> while params will be
rendered as <key=value>. The implementation is mostly copy/pasting from
the builtin _format_items().
This also adds ellipsis if the number of items is greater than
self.n_max_elements_to_show.
"""
write = stream.write
indent += self._indent_per_level
delimnl = ',\n' + ' ' * indent
delim = ''
width = max_width = self._width - indent + 1
it = iter(object)
try:
next_ent = next(it)
except StopIteration:
return
last = False
n_items = 0
while not last:
if n_items == self.n_max_elements_to_show:
write(', ...')
break
n_items += 1
ent = next_ent
try:
next_ent = next(it)
except StopIteration:
last = True
max_width -= allowance
width -= allowance
if self._compact:
k, v = ent
krepr = self._repr(k, context, level)
vrepr = self._repr(v, context, level)
if not is_dict:
krepr = krepr.strip("'")
middle = ': ' if is_dict else '='
rep = krepr + middle + vrepr
w = len(rep) + 2
if width < w:
width = max_width
if delim:
delim = delimnl
if width >= w:
width -= w
write(delim)
delim = ', '
write(rep)
continue
write(delim)
delim = delimnl
class_ = KeyValTuple if is_dict else KeyValTupleParam
self._format(class_(ent), stream, indent,
allowance if last else 1, context, level)
def _format_items(self, items, stream, indent, allowance, context, level):
"""Format the items of an iterable (list, tuple...). Same as the
built-in _format_items, with support for ellipsis if the number of
elements is greater than self.n_max_elements_to_show.
"""
write = stream.write
indent += self._indent_per_level
if self._indent_per_level > 1:
write((self._indent_per_level - 1) * ' ')
delimnl = ',\n' + ' ' * indent
delim = ''
width = max_width = self._width - indent + 1
it = iter(items)
try:
next_ent = next(it)
except StopIteration:
return
last = False
n_items = 0
while not last:
if n_items == self.n_max_elements_to_show:
write(', ...')
break
n_items += 1
ent = next_ent
try:
next_ent = next(it)
except StopIteration:
last = True
max_width -= allowance
width -= allowance
if self._compact:
rep = self._repr(ent, context, level)
w = len(rep) + 2
if width < w:
width = max_width
if delim:
delim = delimnl
if width >= w:
width -= w
write(delim)
delim = ', '
write(rep)
continue
write(delim)
delim = delimnl
self._format(ent, stream, indent,
allowance if last else 1, context, level)
def _pprint_key_val_tuple(self, object, stream, indent, allowance, context,
level):
"""Pretty printing for key-value tuples from dict or parameters."""
k, v = object
rep = self._repr(k, context, level)
if isinstance(object, KeyValTupleParam):
rep = rep.strip("'")
middle = '='
else:
middle = ': '
stream.write(rep)
stream.write(middle)
self._format(v, stream, indent + len(rep) + len(middle), allowance,
context, level)
# Note: need to copy _dispatch to prevent instances of the builtin
# PrettyPrinter class to call methods of _EstimatorPrettyPrinter (see issue
# 12906)
# mypy error: "Type[PrettyPrinter]" has no attribute "_dispatch"
_dispatch = pprint.PrettyPrinter._dispatch.copy() # type: ignore
_dispatch[BaseEstimator.__repr__] = _pprint_estimator
_dispatch[KeyValTuple.__repr__] = _pprint_key_val_tuple
def _safe_repr(object, context, maxlevels, level, changed_only=False):
"""Same as the builtin _safe_repr, with added support for Estimator
objects."""
typ = type(object)
if typ in pprint._builtin_scalars:
return repr(object), True, False
r = getattr(typ, "__repr__", None)
if issubclass(typ, dict) and r is dict.__repr__:
if not object:
return "{}", True, False
objid = id(object)
if maxlevels and level >= maxlevels:
return "{...}", False, objid in context
if objid in context:
return pprint._recursion(object), False, True
context[objid] = 1
readable = True
recursive = False
components = []
append = components.append
level += 1
saferepr = _safe_repr
items = sorted(object.items(), key=pprint._safe_tuple)
for k, v in items:
krepr, kreadable, krecur = saferepr(
k, context, maxlevels, level, changed_only=changed_only)
vrepr, vreadable, vrecur = saferepr(
v, context, maxlevels, level, changed_only=changed_only)
append("%s: %s" % (krepr, vrepr))
readable = readable and kreadable and vreadable
if krecur or vrecur:
recursive = True
del context[objid]
return "{%s}" % ", ".join(components), readable, recursive
if (issubclass(typ, list) and r is list.__repr__) or \
(issubclass(typ, tuple) and r is tuple.__repr__):
if issubclass(typ, list):
if not object:
return "[]", True, False
format = "[%s]"
elif len(object) == 1:
format = "(%s,)"
else:
if not object:
return "()", True, False
format = "(%s)"
objid = id(object)
if maxlevels and level >= maxlevels:
return format % "...", False, objid in context
if objid in context:
return pprint._recursion(object), False, True
context[objid] = 1
readable = True
recursive = False
components = []
append = components.append
level += 1
for o in object:
orepr, oreadable, orecur = _safe_repr(
o, context, maxlevels, level, changed_only=changed_only)
append(orepr)
if not oreadable:
readable = False
if orecur:
recursive = True
del context[objid]
return format % ", ".join(components), readable, recursive
if issubclass(typ, BaseEstimator):
objid = id(object)
if maxlevels and level >= maxlevels:
return "{...}", False, objid in context
if objid in context:
return pprint._recursion(object), False, True
context[objid] = 1
readable = True
recursive = False
if changed_only:
params = _changed_params(object)
else:
params = object.get_params(deep=False)
components = []
append = components.append
level += 1
saferepr = _safe_repr
items = sorted(params.items(), key=pprint._safe_tuple)
for k, v in items:
krepr, kreadable, krecur = saferepr(
k, context, maxlevels, level, changed_only=changed_only)
vrepr, vreadable, vrecur = saferepr(
v, context, maxlevels, level, changed_only=changed_only)
append("%s=%s" % (krepr.strip("'"), vrepr))
readable = readable and kreadable and vreadable
if krecur or vrecur:
recursive = True
del context[objid]
return ("%s(%s)" % (typ.__name__, ", ".join(components)), readable,
recursive)
rep = repr(object)
return rep, (rep and not rep.startswith('<')), False