mirror of
https://github.com/python/cpython.git
synced 2024-11-24 17:47:13 +01:00
536 lines
18 KiB
Python
536 lines
18 KiB
Python
# Author: Fred L. Drake, Jr.
|
|
# fdrake@acm.org
|
|
#
|
|
# This is a simple little module I wrote to make life easier. I didn't
|
|
# see anything quite like it in the library, though I may have overlooked
|
|
# something. I wrote this when I was trying to read some heavily nested
|
|
# tuples with fairly non-descriptive content. This is modeled very much
|
|
# after Lisp/Scheme - style pretty-printing of lists. If you find it
|
|
# useful, thank small children who sleep at night.
|
|
|
|
"""Support to pretty-print lists, tuples, & dictionaries recursively.
|
|
|
|
Very simple, but useful, especially in debugging data structures.
|
|
|
|
Classes
|
|
-------
|
|
|
|
PrettyPrinter()
|
|
Handle pretty-printing operations onto a stream using a configured
|
|
set of formatting parameters.
|
|
|
|
Functions
|
|
---------
|
|
|
|
pformat()
|
|
Format a Python object into a pretty-printed representation.
|
|
|
|
pprint()
|
|
Pretty-print a Python object to a stream [default is sys.stdout].
|
|
|
|
saferepr()
|
|
Generate a 'standard' repr()-like value, but protect against recursive
|
|
data structures.
|
|
|
|
"""
|
|
|
|
import collections as _collections
|
|
import re
|
|
import sys as _sys
|
|
import types as _types
|
|
from io import StringIO as _StringIO
|
|
|
|
__all__ = ["pprint","pformat","isreadable","isrecursive","saferepr",
|
|
"PrettyPrinter"]
|
|
|
|
|
|
def pprint(object, stream=None, indent=1, width=80, depth=None, *,
|
|
compact=False):
|
|
"""Pretty-print a Python object to a stream [default is sys.stdout]."""
|
|
printer = PrettyPrinter(
|
|
stream=stream, indent=indent, width=width, depth=depth,
|
|
compact=compact)
|
|
printer.pprint(object)
|
|
|
|
def pformat(object, indent=1, width=80, depth=None, *, compact=False):
|
|
"""Format a Python object into a pretty-printed representation."""
|
|
return PrettyPrinter(indent=indent, width=width, depth=depth,
|
|
compact=compact).pformat(object)
|
|
|
|
def saferepr(object):
|
|
"""Version of repr() which can handle recursive data structures."""
|
|
return _safe_repr(object, {}, None, 0)[0]
|
|
|
|
def isreadable(object):
|
|
"""Determine if saferepr(object) is readable by eval()."""
|
|
return _safe_repr(object, {}, None, 0)[1]
|
|
|
|
def isrecursive(object):
|
|
"""Determine if object requires a recursive representation."""
|
|
return _safe_repr(object, {}, None, 0)[2]
|
|
|
|
class _safe_key:
|
|
"""Helper function for key functions when sorting unorderable objects.
|
|
|
|
The wrapped-object will fallback to an Py2.x style comparison for
|
|
unorderable types (sorting first comparing the type name and then by
|
|
the obj ids). Does not work recursively, so dict.items() must have
|
|
_safe_key applied to both the key and the value.
|
|
|
|
"""
|
|
|
|
__slots__ = ['obj']
|
|
|
|
def __init__(self, obj):
|
|
self.obj = obj
|
|
|
|
def __lt__(self, other):
|
|
try:
|
|
rv = self.obj.__lt__(other.obj)
|
|
except TypeError:
|
|
rv = NotImplemented
|
|
|
|
if rv is NotImplemented:
|
|
rv = (str(type(self.obj)), id(self.obj)) < \
|
|
(str(type(other.obj)), id(other.obj))
|
|
return rv
|
|
|
|
def _safe_tuple(t):
|
|
"Helper function for comparing 2-tuples"
|
|
return _safe_key(t[0]), _safe_key(t[1])
|
|
|
|
class PrettyPrinter:
|
|
def __init__(self, indent=1, width=80, depth=None, stream=None, *,
|
|
compact=False):
|
|
"""Handle pretty printing operations onto a stream using a set of
|
|
configured parameters.
|
|
|
|
indent
|
|
Number of spaces to indent for each level of nesting.
|
|
|
|
width
|
|
Attempted maximum number of columns in the output.
|
|
|
|
depth
|
|
The maximum depth to print out nested structures.
|
|
|
|
stream
|
|
The desired output stream. If omitted (or false), the standard
|
|
output stream available at construction will be used.
|
|
|
|
compact
|
|
If true, several items will be combined in one line.
|
|
|
|
"""
|
|
indent = int(indent)
|
|
width = int(width)
|
|
if indent < 0:
|
|
raise ValueError('indent must be >= 0')
|
|
if depth is not None and depth <= 0:
|
|
raise ValueError('depth must be > 0')
|
|
if not width:
|
|
raise ValueError('width must be != 0')
|
|
self._depth = depth
|
|
self._indent_per_level = indent
|
|
self._width = width
|
|
if stream is not None:
|
|
self._stream = stream
|
|
else:
|
|
self._stream = _sys.stdout
|
|
self._compact = bool(compact)
|
|
|
|
def pprint(self, object):
|
|
self._format(object, self._stream, 0, 0, {}, 0)
|
|
self._stream.write("\n")
|
|
|
|
def pformat(self, object):
|
|
sio = _StringIO()
|
|
self._format(object, sio, 0, 0, {}, 0)
|
|
return sio.getvalue()
|
|
|
|
def isrecursive(self, object):
|
|
return self.format(object, {}, 0, 0)[2]
|
|
|
|
def isreadable(self, object):
|
|
s, readable, recursive = self.format(object, {}, 0, 0)
|
|
return readable and not recursive
|
|
|
|
def _format(self, object, stream, indent, allowance, context, level):
|
|
objid = id(object)
|
|
if objid in context:
|
|
stream.write(_recursion(object))
|
|
self._recursive = True
|
|
self._readable = False
|
|
return
|
|
rep = self._repr(object, context, level)
|
|
max_width = self._width - indent - allowance
|
|
if len(rep) > max_width:
|
|
p = self._dispatch.get(type(object).__repr__, None)
|
|
if p is not None:
|
|
context[objid] = 1
|
|
p(self, object, stream, indent, allowance, context, level + 1)
|
|
del context[objid]
|
|
return
|
|
elif isinstance(object, dict):
|
|
context[objid] = 1
|
|
self._pprint_dict(object, stream, indent, allowance,
|
|
context, level + 1)
|
|
del context[objid]
|
|
return
|
|
stream.write(rep)
|
|
|
|
_dispatch = {}
|
|
|
|
def _pprint_dict(self, object, stream, indent, allowance, context, level):
|
|
write = stream.write
|
|
write('{')
|
|
if self._indent_per_level > 1:
|
|
write((self._indent_per_level - 1) * ' ')
|
|
length = len(object)
|
|
if length:
|
|
items = sorted(object.items(), key=_safe_tuple)
|
|
self._format_dict_items(items, stream, indent, allowance + 1,
|
|
context, level)
|
|
write('}')
|
|
|
|
_dispatch[dict.__repr__] = _pprint_dict
|
|
|
|
def _pprint_ordered_dict(self, object, stream, indent, allowance, context, level):
|
|
if not len(object):
|
|
stream.write(repr(object))
|
|
return
|
|
cls = object.__class__
|
|
stream.write(cls.__name__ + '(')
|
|
self._format(list(object.items()), stream,
|
|
indent + len(cls.__name__) + 1, allowance + 1,
|
|
context, level)
|
|
stream.write(')')
|
|
|
|
_dispatch[_collections.OrderedDict.__repr__] = _pprint_ordered_dict
|
|
|
|
def _pprint_list(self, object, stream, indent, allowance, context, level):
|
|
stream.write('[')
|
|
self._format_items(object, stream, indent, allowance + 1,
|
|
context, level)
|
|
stream.write(']')
|
|
|
|
_dispatch[list.__repr__] = _pprint_list
|
|
|
|
def _pprint_tuple(self, object, stream, indent, allowance, context, level):
|
|
stream.write('(')
|
|
endchar = ',)' if len(object) == 1 else ')'
|
|
self._format_items(object, stream, indent, allowance + len(endchar),
|
|
context, level)
|
|
stream.write(endchar)
|
|
|
|
_dispatch[tuple.__repr__] = _pprint_tuple
|
|
|
|
def _pprint_set(self, object, stream, indent, allowance, context, level):
|
|
if not len(object):
|
|
stream.write(repr(object))
|
|
return
|
|
typ = object.__class__
|
|
if typ is set:
|
|
stream.write('{')
|
|
endchar = '}'
|
|
else:
|
|
stream.write(typ.__name__ + '({')
|
|
endchar = '})'
|
|
indent += len(typ.__name__) + 1
|
|
object = sorted(object, key=_safe_key)
|
|
self._format_items(object, stream, indent, allowance + len(endchar),
|
|
context, level)
|
|
stream.write(endchar)
|
|
|
|
_dispatch[set.__repr__] = _pprint_set
|
|
_dispatch[frozenset.__repr__] = _pprint_set
|
|
|
|
def _pprint_str(self, object, stream, indent, allowance, context, level):
|
|
write = stream.write
|
|
if not len(object):
|
|
write(repr(object))
|
|
return
|
|
chunks = []
|
|
lines = object.splitlines(True)
|
|
if level == 1:
|
|
indent += 1
|
|
allowance += 1
|
|
max_width1 = max_width = self._width - indent
|
|
for i, line in enumerate(lines):
|
|
rep = repr(line)
|
|
if i == len(lines) - 1:
|
|
max_width1 -= allowance
|
|
if len(rep) <= max_width1:
|
|
chunks.append(rep)
|
|
else:
|
|
# A list of alternating (non-space, space) strings
|
|
parts = re.findall(r'\S*\s*', line)
|
|
assert parts
|
|
assert not parts[-1]
|
|
parts.pop() # drop empty last part
|
|
max_width2 = max_width
|
|
current = ''
|
|
for j, part in enumerate(parts):
|
|
candidate = current + part
|
|
if j == len(parts) - 1 and i == len(lines) - 1:
|
|
max_width2 -= allowance
|
|
if len(repr(candidate)) > max_width2:
|
|
if current:
|
|
chunks.append(repr(current))
|
|
current = part
|
|
else:
|
|
current = candidate
|
|
if current:
|
|
chunks.append(repr(current))
|
|
if len(chunks) == 1:
|
|
write(rep)
|
|
return
|
|
if level == 1:
|
|
write('(')
|
|
for i, rep in enumerate(chunks):
|
|
if i > 0:
|
|
write('\n' + ' '*indent)
|
|
write(rep)
|
|
if level == 1:
|
|
write(')')
|
|
|
|
_dispatch[str.__repr__] = _pprint_str
|
|
|
|
def _pprint_bytes(self, object, stream, indent, allowance, context, level):
|
|
write = stream.write
|
|
if len(object) <= 4:
|
|
write(repr(object))
|
|
return
|
|
parens = level == 1
|
|
if parens:
|
|
indent += 1
|
|
allowance += 1
|
|
write('(')
|
|
delim = ''
|
|
for rep in _wrap_bytes_repr(object, self._width - indent, allowance):
|
|
write(delim)
|
|
write(rep)
|
|
if not delim:
|
|
delim = '\n' + ' '*indent
|
|
if parens:
|
|
write(')')
|
|
|
|
_dispatch[bytes.__repr__] = _pprint_bytes
|
|
|
|
def _pprint_bytearray(self, object, stream, indent, allowance, context, level):
|
|
write = stream.write
|
|
write('bytearray(')
|
|
self._pprint_bytes(bytes(object), stream, indent + 10,
|
|
allowance + 1, context, level + 1)
|
|
write(')')
|
|
|
|
_dispatch[bytearray.__repr__] = _pprint_bytearray
|
|
|
|
def _pprint_mappingproxy(self, object, stream, indent, allowance, context, level):
|
|
stream.write('mappingproxy(')
|
|
self._format(object.copy(), stream, indent + 13, allowance + 1,
|
|
context, level)
|
|
stream.write(')')
|
|
|
|
_dispatch[_types.MappingProxyType.__repr__] = _pprint_mappingproxy
|
|
|
|
def _format_dict_items(self, items, stream, indent, allowance, context,
|
|
level):
|
|
write = stream.write
|
|
indent += self._indent_per_level
|
|
delimnl = ',\n' + ' ' * indent
|
|
last_index = len(items) - 1
|
|
for i, (key, ent) in enumerate(items):
|
|
last = i == last_index
|
|
rep = self._repr(key, context, level)
|
|
write(rep)
|
|
write(': ')
|
|
self._format(ent, stream, indent + len(rep) + 2,
|
|
allowance if last else 1,
|
|
context, level)
|
|
if not last:
|
|
write(delimnl)
|
|
|
|
def _format_items(self, items, stream, indent, allowance, context, level):
|
|
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
|
|
while not last:
|
|
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 _repr(self, object, context, level):
|
|
repr, readable, recursive = self.format(object, context.copy(),
|
|
self._depth, level)
|
|
if not readable:
|
|
self._readable = False
|
|
if recursive:
|
|
self._recursive = True
|
|
return repr
|
|
|
|
def format(self, object, context, maxlevels, level):
|
|
"""Format object for a specific context, returning a string
|
|
and flags indicating whether the representation is 'readable'
|
|
and whether the object represents a recursive construct.
|
|
"""
|
|
return _safe_repr(object, context, maxlevels, level)
|
|
|
|
|
|
# Return triple (repr_string, isreadable, isrecursive).
|
|
|
|
def _safe_repr(object, context, maxlevels, level):
|
|
typ = type(object)
|
|
if typ is str:
|
|
if 'locale' not in _sys.modules:
|
|
return repr(object), True, False
|
|
if "'" in object and '"' not in object:
|
|
closure = '"'
|
|
quotes = {'"': '\\"'}
|
|
else:
|
|
closure = "'"
|
|
quotes = {"'": "\\'"}
|
|
qget = quotes.get
|
|
sio = _StringIO()
|
|
write = sio.write
|
|
for char in object:
|
|
if char.isalpha():
|
|
write(char)
|
|
else:
|
|
write(qget(char, repr(char)[1:-1]))
|
|
return ("%s%s%s" % (closure, sio.getvalue(), closure)), 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 _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=_safe_tuple)
|
|
for k, v in items:
|
|
krepr, kreadable, krecur = saferepr(k, context, maxlevels, level)
|
|
vrepr, vreadable, vrecur = saferepr(v, context, maxlevels, level)
|
|
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 _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)
|
|
append(orepr)
|
|
if not oreadable:
|
|
readable = False
|
|
if orecur:
|
|
recursive = True
|
|
del context[objid]
|
|
return format % ", ".join(components), readable, recursive
|
|
|
|
rep = repr(object)
|
|
return rep, (rep and not rep.startswith('<')), False
|
|
|
|
|
|
def _recursion(object):
|
|
return ("<Recursion on %s with id=%s>"
|
|
% (type(object).__name__, id(object)))
|
|
|
|
|
|
def _perfcheck(object=None):
|
|
import time
|
|
if object is None:
|
|
object = [("string", (1, 2), [3, 4], {5: 6, 7: 8})] * 100000
|
|
p = PrettyPrinter()
|
|
t1 = time.time()
|
|
_safe_repr(object, {}, None, 0)
|
|
t2 = time.time()
|
|
p.pformat(object)
|
|
t3 = time.time()
|
|
print("_safe_repr:", t2 - t1)
|
|
print("pformat:", t3 - t2)
|
|
|
|
def _wrap_bytes_repr(object, width, allowance):
|
|
current = b''
|
|
last = len(object) // 4 * 4
|
|
for i in range(0, len(object), 4):
|
|
part = object[i: i+4]
|
|
candidate = current + part
|
|
if i == last:
|
|
width -= allowance
|
|
if len(repr(candidate)) > width:
|
|
if current:
|
|
yield repr(current)
|
|
current = part
|
|
else:
|
|
current = candidate
|
|
if current:
|
|
yield repr(current)
|
|
|
|
if __name__ == "__main__":
|
|
_perfcheck()
|