cpython/Lib/reprlib.py

162 lines
5.1 KiB
Python

"""Redo the builtin repr() (representation) but with limits on most sizes."""
__all__ = ["Repr", "repr", "recursive_repr"]
import builtins
from itertools import islice
try:
from _thread import get_ident
except ImportError:
from _dummy_thread import get_ident
def recursive_repr(fillvalue='...'):
'Decorator to make a repr function return fillvalue for a recursive call'
def decorating_function(user_function):
repr_running = set()
def wrapper(self):
key = id(self), get_ident()
if key in repr_running:
return fillvalue
repr_running.add(key)
try:
result = user_function(self)
finally:
repr_running.discard(key)
return result
# Can't use functools.wraps() here because of bootstrap issues
wrapper.__module__ = getattr(user_function, '__module__')
wrapper.__doc__ = getattr(user_function, '__doc__')
wrapper.__name__ = getattr(user_function, '__name__')
wrapper.__annotations__ = getattr(user_function, '__annotations__', {})
return wrapper
return decorating_function
class Repr:
def __init__(self):
self.maxlevel = 6
self.maxtuple = 6
self.maxlist = 6
self.maxarray = 5
self.maxdict = 4
self.maxset = 6
self.maxfrozenset = 6
self.maxdeque = 6
self.maxstring = 30
self.maxlong = 40
self.maxother = 30
def repr(self, x):
return self.repr1(x, self.maxlevel)
def repr1(self, x, level):
typename = type(x).__name__
if ' ' in typename:
parts = typename.split()
typename = '_'.join(parts)
if hasattr(self, 'repr_' + typename):
return getattr(self, 'repr_' + typename)(x, level)
else:
return self.repr_instance(x, level)
def _repr_iterable(self, x, level, left, right, maxiter, trail=''):
n = len(x)
if level <= 0 and n:
s = '...'
else:
newlevel = level - 1
repr1 = self.repr1
pieces = [repr1(elem, newlevel) for elem in islice(x, maxiter)]
if n > maxiter: pieces.append('...')
s = ', '.join(pieces)
if n == 1 and trail: right = trail + right
return '%s%s%s' % (left, s, right)
def repr_tuple(self, x, level):
return self._repr_iterable(x, level, '(', ')', self.maxtuple, ',')
def repr_list(self, x, level):
return self._repr_iterable(x, level, '[', ']', self.maxlist)
def repr_array(self, x, level):
header = "array('%s', [" % x.typecode
return self._repr_iterable(x, level, header, '])', self.maxarray)
def repr_set(self, x, level):
if not x:
return 'set()'
x = _possibly_sorted(x)
return self._repr_iterable(x, level, '{', '}', self.maxset)
def repr_frozenset(self, x, level):
if not x:
return 'frozenset()'
x = _possibly_sorted(x)
return self._repr_iterable(x, level, 'frozenset({', '})',
self.maxfrozenset)
def repr_deque(self, x, level):
return self._repr_iterable(x, level, 'deque([', '])', self.maxdeque)
def repr_dict(self, x, level):
n = len(x)
if n == 0: return '{}'
if level <= 0: return '{...}'
newlevel = level - 1
repr1 = self.repr1
pieces = []
for key in islice(_possibly_sorted(x), self.maxdict):
keyrepr = repr1(key, newlevel)
valrepr = repr1(x[key], newlevel)
pieces.append('%s: %s' % (keyrepr, valrepr))
if n > self.maxdict: pieces.append('...')
s = ', '.join(pieces)
return '{%s}' % (s,)
def repr_str(self, x, level):
s = builtins.repr(x[:self.maxstring])
if len(s) > self.maxstring:
i = max(0, (self.maxstring-3)//2)
j = max(0, self.maxstring-3-i)
s = builtins.repr(x[:i] + x[len(x)-j:])
s = s[:i] + '...' + s[len(s)-j:]
return s
def repr_int(self, x, level):
s = builtins.repr(x) # XXX Hope this isn't too slow...
if len(s) > self.maxlong:
i = max(0, (self.maxlong-3)//2)
j = max(0, self.maxlong-3-i)
s = s[:i] + '...' + s[len(s)-j:]
return s
def repr_instance(self, x, level):
try:
s = builtins.repr(x)
# Bugs in x.__repr__() can cause arbitrary
# exceptions -- then make up something
except Exception:
return '<%s instance at %#x>' % (x.__class__.__name__, id(x))
if len(s) > self.maxother:
i = max(0, (self.maxother-3)//2)
j = max(0, self.maxother-3-i)
s = s[:i] + '...' + s[len(s)-j:]
return s
def _possibly_sorted(x):
# Since not all sequences of items can be sorted and comparison
# functions may raise arbitrary exceptions, return an unsorted
# sequence in that case.
try:
return sorted(x)
except Exception:
return list(x)
aRepr = Repr()
repr = aRepr.repr