def _assertReplacer(self, arg, replacements=None):
self.assertIsInstance(arg, __unit__.Replacer)
if replacements is not None:
if is_mapping(replacements):
self.assertEquals(replacements, arg._replacements)
else:
self.assertItemsEqual(replacements, arg._replacements)
self.assertFalse(is_mapping(arg._replacements))
def _assertReplacer(self, arg, replacements=None):
self.assertIsInstance(arg, __unit__.Replacer)
if replacements is not None:
if is_mapping(replacements):
self.assertEquals(replacements, arg._replacements)
else:
self.assertItemsEqual(replacements, arg._replacements)
self.assertFalse(is_mapping(arg._replacements))
def in_(self, haystack):
"""Perform replacement in given string.
:param haystack: String to perform replacements in
:return: ``haystack`` after the replacements
:raise TypeError: If ``haystack`` if not a string
:raise ReplacementError: If no replacement(s) have been provided yet
"""
from taipan.collections import dicts
ensure_string(haystack)
if not is_mapping(self._replacements):
raise ReplacementError("string replacements not provided")
# handle special cases
if not self._replacements:
return haystack
if len(self._replacements) == 1:
return haystack.replace(*dicts.peekitem(self._replacements))
# construct a regex matching any of the needles in the order
# of descending length (to prevent issues if they contain each other)
or_ = haystack.__class__('|')
regex = join(or_, imap(
re.escape, sorted(self._replacements, key=len, reverse=True)))
# do the substituion, looking up the replacement for every match
do_replace = lambda match: self._replacements[match.group()]
return re.sub(regex, do_replace, haystack)
def in_(self, haystack):
"""Perform replacement in given string.
:param haystack: String to perform replacements in
:return: ``haystack`` after the replacements
:raise TypeError: If ``haystack`` if not a string
:raise ReplacementError: If no replacement(s) have been provided yet
"""
from taipan.collections import dicts
ensure_string(haystack)
if not is_mapping(self._replacements):
raise ReplacementError("string replacements not provided")
# handle special cases
if not self._replacements:
return haystack
if len(self._replacements) == 1:
return haystack.replace(*dicts.peekitem(self._replacements))
# construct a regex matching any of the needles in the order
# of descending length (to prevent issues if they contain each other)
or_ = haystack.__class__('|')
regex = join(
or_,
imap(re.escape, sorted(self._replacements, key=len, reverse=True)))
# do the substituion, looking up the replacement for every match
do_replace = lambda match: self._replacements[match.group()]
return re.sub(regex, do_replace, haystack)
def replace(needle, with_=None, in_=None):
"""Replace occurrences of string(s) with other string(s) in (a) string(s).
Unlike the built in :meth:`str.replace` method, this function provides
clean API that clearly distinguishes the "needle" (string to replace),
the replacement string, and the target string to perform replacement in
(the "haystack").
Additionally, a simultaneous replacement of several needles is possible.
Note that this is different from performing multiple separate replacements
one after another.
Examples::
replace('foo', with_='bar', in_=some_text)
replace('foo', with_='bar').in_(other_text)
replace('foo').with_('bar').in_(another_text)
replace(['foo', 'bar']).with_('baz').in_(perhaps_a_long_text)
replace({'foo': 'bar', 'baz': 'qud'}).in_(even_longer_text)
:param needle: String to replace, iterable thereof,
or a mapping from needles to corresponding replacements
:param with_: Replacement string, if ``needle`` was not a mapping
:param in_: Optional string to perform replacement in
:return: If all parameters were provided, result is the final string
after performing a specified replacement.
Otherwise, a :class:`Replacer` object is returned, allowing
e.g. to perform the same replacements in many haystacks.
"""
if needle is None:
raise TypeError("replacement needle cannot be None")
if not needle:
raise ValueError("replacement needle cannot be empty")
if is_string(needle):
replacer = Replacer((needle,))
else:
ensure_iterable(needle)
if not is_mapping(needle):
if all(imap(is_pair, needle)):
needle = dict(needle)
elif not all(imap(is_string, needle)):
raise TypeError("invalid replacement needle")
replacer = Replacer(needle)
if with_ is not None:
ensure_string(with_)
replacer = replacer.with_(with_)
if in_ is not None:
ensure_string(in_)
return replacer.in_(in_)
return replacer
def replace(needle, with_=None, in_=None):
"""Replace occurrences of string(s) with other string(s) in (a) string(s).
Unlike the built in :meth:`str.replace` method, this function provides
clean API that clearly distinguishes the "needle" (string to replace),
the replacement string, and the target string to perform replacement in
(the "haystack").
Additionally, a simultaneous replacement of several needles is possible.
Note that this is different from performing multiple separate replacements
one after another.
Examples::
replace('foo', with_='bar', in_=some_text)
replace('foo', with_='bar').in_(other_text)
replace('foo').with_('bar').in_(another_text)
replace(['foo', 'bar']).with_('baz').in_(perhaps_a_long_text)
replace({'foo': 'bar', 'baz': 'qud'}).in_(even_longer_text)
:param needle: String to replace, iterable thereof,
or a mapping from needles to corresponding replacements
:param with_: Replacement string, if ``needle`` was not a mapping
:param in_: Optional string to perform replacement in
:return: If all parameters were provided, result is the final string
after performing a specified replacement.
Otherwise, a :class:`Replacer` object is returned, allowing
e.g. to perform the same replacements in many haystacks.
"""
if needle is None:
raise TypeError("replacement needle cannot be None")
if not needle:
raise ValueError("replacement needle cannot be empty")
if is_string(needle):
replacer = Replacer((needle, ))
else:
ensure_iterable(needle)
if not is_mapping(needle):
if all(imap(is_pair, needle)):
needle = dict(needle)
elif not all(imap(is_string, needle)):
raise TypeError("invalid replacement needle")
replacer = Replacer(needle)
if with_ is not None:
ensure_string(with_)
replacer = replacer.with_(with_)
if in_ is not None:
ensure_string(in_)
return replacer.in_(in_)
return replacer
def _recursive_dict_update(dict_, other, **kwargs):
"""Deep/recursive version of ``dict.update``.
If a key is present in both dictionaries, and points to
"child" dictionaries, those will be appropriately merged.
:param overwrite: Whether to overwrite exisiting dictionary values
"""
overwrite = kwargs['overwrite']
for key, other_value in iteritems(other):
if key in dict_:
value = dict_[key]
if is_mapping(value) and is_mapping(other_value):
_recursive_dict_update(value, other_value, overwrite=overwrite)
continue
if overwrite:
dict_[key] = other_value
else:
dict_.setdefault(key, other_value)
def with_(self, replacement):
"""Provide replacement for string "needles".
:param replacement: Target replacement for needles given in constructor
:return: The :class:`Replacement` object
:raise TypeError: If ``replacement`` is not a string
:raise ReplacementError: If replacement has been already given
"""
ensure_string(replacement)
if is_mapping(self._replacements):
raise ReplacementError("string replacements already provided")
self._replacements = dict.fromkeys(self._replacements, replacement)
return self
def with_(self, replacement):
"""Provide replacement for string "needles".
:param replacement: Target replacement for needles given in constructor
:return: The :class:`Replacement` object
:raise TypeError: If ``replacement`` is not a string
:raise ReplacementError: If replacement has been already given
"""
ensure_string(replacement)
if is_mapping(self._replacements):
raise ReplacementError("string replacements already provided")
self._replacements = dict.fromkeys(self._replacements, replacement)
return self
def merge(arg, *rest, **kwargs):
"""Merge a collection, with functions as items, into a single function
that takes a collection and maps its items through corresponding functions.
:param arg: A collection of functions, such as list, tuple, or dictionary
:param default: Optional default function to use for items
within merged function's arguments that do not have
corresponding functions in ``arg``
Example with two-element tuple::
>> dict_ = {'Alice': -5, 'Bob': 4}
>> func = merge((str.upper, abs))
>> dict(map(func, dict_.items()))
{'ALICE': 5, 'BOB': 4}
Example with a dictionary::
>> func = merge({'id': int, 'name': str.split})
>> data = [
{'id': '1', 'name': "John Doe"},
{'id': '2', 'name': "Anne Arbor"},
]
>> list(map(func, data))
[{'id': 1, 'name': ['John', 'Doe']},
{'id': 2, 'name': ['Anne', 'Arbor']}]
:return: Merged function
.. versionadded:: 0.0.2
"""
ensure_keyword_args(kwargs, optional=('default', ))
has_default = 'default' in kwargs
if has_default:
default = ensure_callable(kwargs['default'])
# if more than one argument was given, they must all be functions;
# result will be a function that takes multiple arguments (rather than
# a single collection) and returns a tuple
unary_result = True
if rest:
fs = (ensure_callable(arg), ) + tuple(imap(ensure_callable, rest))
unary_result = False
else:
fs = arg
if is_mapping(fs):
if has_default:
return lambda arg_: fs.__class__(
(k, fs.get(k, default)(arg_[k])) for k in arg_)
else:
return lambda arg_: fs.__class__((k, fs[k](arg_[k])) for k in arg_)
else:
ensure_sequence(fs)
if has_default:
# we cannot use ``izip_longest(fs, arg_, fillvalue=default)``,
# because we want to terminate the generator
# only when ``arg_`` is exhausted (not when just ``fs`` is)
func = lambda arg_: fs.__class__((fs[i]
if i < len(fs) else default)(x)
for i, x in enumerate(arg_))
else:
# we cannot use ``izip(fs, arg_)`` because it would short-circuit
# if ``arg_`` is longer than ``fs``, rather than raising
# the required ``IndexError``
func = lambda arg_: fs.__class__(fs[i](x)
for i, x in enumerate(arg_))
return func if unary_result else lambda *args: func(args)
def _assertIsMapping(self, obj, msg=None):
if not is_mapping(obj):
self.fail(msg or "%r is not a mapping" % (obj, ))
def try_(block, except_=None, else_=None, finally_=None):
"""Emulate a ``try`` block.
:param block: Function to be executed within the ``try`` statement
:param except_: Function to execute when an :class:`Exception` occurs.
It receives a single argument: the exception object.
Alternatively, a list of key-value pairs can be passed,
mapping exception types to their handler functions.
:param else_: Function to execute when ``block`` completes successfully.
Note that it requires ``except_`` to be provided as well
:param finally_: Function to execute at the end,
regardless of whether an exception occurred or not
:return: If no exception was raised while executing ``block``,
the result of ``else_`` (if provided) or ``block`` is returned.
Otherwise, the result of ``except_`` is returned.
Note that :func:`try_` can _still_ raise an exception if it occurs
while evaluating ``except_``, ``else_`` or ``finally_`` functions.
"""
ensure_callable(block)
if not (except_ or else_ or finally_):
raise TypeError("at least one of `except_`, `else_` or `finally_` "
"functions must be provided")
if else_ and not except_:
raise TypeError("`else_` can only be provided along with `except_`")
if except_:
if callable(except_):
except_ = [(Exception, except_)]
else:
ensure_iterable(except_)
if is_mapping(except_):
ensure_ordered_mapping(except_)
except_ = except_.items()
def handle_exception():
"""Dispatch current exception to proper handler in ``except_``."""
exc_type, exc_object = sys.exc_info()[:2]
for t, handler in except_:
if issubclass(exc_type, t):
return handler(exc_object)
raise
if else_:
ensure_callable(else_)
if finally_:
ensure_callable(finally_)
try:
block()
except:
return handle_exception()
else:
return else_()
finally:
finally_()
else:
try:
block()
except:
return handle_exception()
else:
return else_()
else:
if finally_:
ensure_callable(finally_)
try:
return block()
except:
return handle_exception()
finally:
finally_()
else:
try:
return block()
except:
return handle_exception()
elif finally_:
ensure_callable(finally_)
try:
return block()
finally:
finally_()
def try_(block, except_=None, else_=None, finally_=None):
"""Emulate a ``try`` block.
:param block: Function to be executed within the ``try`` statement
:param except_: Function to execute when an :class:`Exception` occurs.
It receives a single argument: the exception object.
Alternatively, a list of key-value pairs can be passed,
mapping exception types to their handler functions.
:param else_: Function to execute when ``block`` completes successfully.
Note that it requires ``except_`` to be provided as well
:param finally_: Function to execute at the end,
regardless of whether an exception occurred or not
:return: If no exception was raised while executing ``block``,
the result of ``else_`` (if provided) or ``block`` is returned.
Otherwise, the result of ``except_`` is returned.
Note that :func:`try_` can _still_ raise an exception if it occurs
while evaluating ``except_``, ``else_`` or ``finally_`` functions.
"""
ensure_callable(block)
if not (except_ or else_ or finally_):
raise TypeError("at least one of `except_`, `else_` or `finally_` "
"functions must be provided")
if else_ and not except_:
raise TypeError("`else_` can only be provided along with `except_`")
if except_:
if callable(except_):
except_ = [(Exception, except_)]
else:
ensure_iterable(except_)
if is_mapping(except_):
ensure_ordered_mapping(except_)
except_ = except_.items()
def handle_exception():
"""Dispatch current exception to proper handler in ``except_``."""
exc_type, exc_object = sys.exc_info()[:2]
for t, handler in except_:
if issubclass(exc_type, t):
return handler(exc_object)
raise
if else_:
ensure_callable(else_)
if finally_:
ensure_callable(finally_)
try:
block()
except:
return handle_exception()
else:
return else_()
finally:
finally_()
else:
try:
block()
except:
return handle_exception()
else:
return else_()
else:
if finally_:
ensure_callable(finally_)
try:
return block()
except:
return handle_exception()
finally:
finally_()
else:
try:
return block()
except:
return handle_exception()
elif finally_:
ensure_callable(finally_)
try:
return block()
finally:
finally_()
def __init__(self, iterable=(), **kwargs):
if is_mapping(iterable):
iterable = iteritems(iterable)
super(AbsentDict, self).__init__(
chain(((k, v) for k, v in iterable if v is not ABSENT),
((k, v) for k, v in iteritems(kwargs) if v is not ABSENT)))
def _assertIsMapping(self, obj, msg=None):
if not is_mapping(obj):
self.fail(msg or "%r is not a mapping" % (obj,))
