GlobFormatter.convert_field() - Code Metrics - Inspection of "[WIP] Implement match()" - jacebrowning/yorm - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Pull Request — develop (#143)

unknown

created 2017-05-31 19:16 UTC

GlobFormatter.convert_field() A

↳ Parent: GlobFormatter

Complexity

Conditions

Size

Total Lines

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	2
CRAP Score	2

Importance

Changes

Metric	Value
c	0
b	0
f	0
dl	0
loc	5
ccs	2
cts	2
cp	1
rs	9.4285
cc	2
crap	2

"""Functions to interact with mapped classes and instances."""

import inspect
import logging
import string
import glob
import types
import parse

from . import common, exceptions

log = logging.getLogger(__name__)



def create(class_or_instance, *args, overwrite=False, **kwargs):
    """Create a new mapped object.

    NOTE: Calling this function is unnecessary with 'auto_create' enabled.

    """
    instance = _instantiate(class_or_instance, *args, **kwargs)
    mapper = common.get_mapper(instance, expected=True)

    if mapper.exists and not overwrite:
        msg = "{!r} already exists".format(mapper.path)
        raise exceptions.DuplicateMappingError(msg)

    return load(save(instance))


def find(class_or_instance, *args, create=False, **kwargs):  # pylint: disable=redefined-outer-name

    """Find a matching mapped object or return None."""
    instance = _instantiate(class_or_instance, *args, **kwargs)
    mapper = common.get_mapper(instance, expected=True)

    if mapper.exists:
        return instance
    elif create:
        return save(instance)
    else:
        return None


class GlobFormatter(string.Formatter):
    """
    Uses '*' for all unknown fields
    """

    WILDCARD = object()

    def get_value(self, key, args, kwargs):
        try:
            return super().get_value(key, args, kwargs)
        except (KeyError, IndexError):
            return self.WILDCARD

    def convert_field(self, value, conversion):
        if value is self.WILDCARD:
            return self.WILDCARD
        else:
            return super().convert_field(value, conversion)

    def format_field(self, value, format_spec):
        if value is self.WILDCARD:
            return '*'
        else:
            return super().format_field(value, format_spec)


def _unpack_parsed_fields(pathfields):
class SomeClass:
    def some_method(self):
        """Do x and return foo."""
    return {
        (k[len('self.'):] if k.startswith('self.') else k): v
        for k, v in pathfields.items()
    }


def match(cls_or_path, factory=None, **kwargs):
    """match(class, [callable], ...) -> instance, ...
    match(str, callable, ...) -> instance, ...

    Yield all matching mapped objects. Can be used two ways:
    * With a YORM-decorated class, optionally with a factory callable
    * With a Python 3-style string template and a factory callable

    The factory callable must accept keyuword arguments, extracted from the file
    name merged with those passed to match(). If no factory is given, the class
    itself is used as the factory (same signature).
    """
    if isinstance(cls_or_path, type):
        path_format = common.path_formats[cls_or_path]
        # Let KeyError fail through
        if factory is None:
            factory = cls_or_path
    else:
        path_format = cls_or_path
        if factory is None:
            raise TypeError("Factory must be given if a string template is used")

    log.debug((path_format, factory, kwargs))
    gf = GlobFormatter()

    mock = types.SimpleNamespace(**kwargs)

    kwargs['self'] = mock
    posix_pattern = gf.vformat(path_format, (), kwargs)
    py_pattern = parse.compile(path_format)


    for filename in glob.iglob(posix_pattern, recursive=False):

        pathfields = py_pattern.parse(filename).named
        fields = _unpack_parsed_fields(pathfields)
        fields.update(kwargs)
        yield factory(**fields)



def load(instance):
    """Force the loading of a mapped object's file.

    NOTE: Calling this function is unnecessary. It exists for the
        aesthetic purpose of having symmetry between save and load.

    """
    mapper = common.get_mapper(instance, expected=True)

    mapper.load()

    return instance


def save(instance):
    """Save a mapped object to file.

    NOTE: Calling this function is unnecessary with 'auto_save' enabled.

    """
    mapper = common.get_mapper(instance, expected=True)

    if mapper.deleted:
        msg = "{!r} was deleted".format(mapper.path)
        raise exceptions.DeletedFileError(msg)

    if not mapper.exists:
        mapper.create()

    mapper.save()

    return instance


def delete(instance):
    """Delete a mapped object's file."""
    mapper = common.get_mapper(instance, expected=True)

    mapper.delete()

    return None


def _instantiate(class_or_instance, *args, **kwargs):
class SomeClass:
    def some_method(self):
        """Do x and return foo."""
    if inspect.isclass(class_or_instance):
        instance = class_or_instance(*args, **kwargs)
    else:
        assert not args
        instance = class_or_instance

    return instance


1		"""Functions to interact with mapped classes and instances."""
2
3	1	import inspect
4	1	import logging
5		import string
6	1	import glob
7		import types
8	1	import parse
9
10		from . import common, exceptions
11	1
12		log = logging.getLogger(__name__)
		0 ignored issues – show Coding Style Naming introduced 2017-01-24 21:22 UTC by Report Bug Copy Issue Report The name `log` does not conform to the constant naming conventions (`(([A-Z_][A-Z0-9_])\|(__.__))$`). This check looks for invalid names for a range of different identifiers. You can set regular expressions to which the identifiers must conform if the defaults do not match your requirements. If your project includes a Pylint configuration file, the settings contained in that file take precedence. To find out more about Pylint, please refer to their site. Loading history...
13
14
15		def create(class_or_instance, args, overwrite=False, *kwargs):
16		"""Create a new mapped object.
17	1
18	1	NOTE: Calling this function is unnecessary with 'auto_create' enabled.
19
20	1	"""
21	1	instance = _instantiate(class_or_instance, args, *kwargs)
22	1	mapper = common.get_mapper(instance, expected=True)
23
24	1	if mapper.exists and not overwrite:
25		msg = "{!r} already exists".format(mapper.path)
26		raise exceptions.DuplicateMappingError(msg)
27	1
28		return load(save(instance))
29	1
30	1
31		def find(class_or_instance, args, create=False, *kwargs): # pylint: disable=redefined-outer-name
		0 ignored issues – show introduced 2017-01-24 21:22 UTC by Report Bug Copy Issue Report Locally disabling redefined-outer-name (W0621) Loading history...
32	1	"""Find a matching mapped object or return None."""
33	1	instance = _instantiate(class_or_instance, args, *kwargs)
34	1	mapper = common.get_mapper(instance, expected=True)
35	1
36		if mapper.exists:
37	1	return instance
38		elif create:
39		return save(instance)
40	1	else:
41		return None
42	1
43	1
44		class GlobFormatter(string.Formatter):
45		"""
46	1	Uses '*' for all unknown fields
47		"""
48
49		WILDCARD = object()
50
51		def get_value(self, key, args, kwargs):
52		try:
53	1	return super().get_value(key, args, kwargs)
54		except (KeyError, IndexError):
55	1	return self.WILDCARD
56
57	1	def convert_field(self, value, conversion):
58		if value is self.WILDCARD:
59		return self.WILDCARD
60	1	else:
61		return super().convert_field(value, conversion)
62
63		def format_field(self, value, format_spec):
64		if value is self.WILDCARD:
65		return '*'
66	1	else:
67		return super().format_field(value, format_spec)
68	1
69	1
70	1	def _unpack_parsed_fields(pathfields):
		0 ignored issues – show Coding Style introduced 2017-05-30 20:35 UTC by Report Bug Copy Issue Report This function should have a docstring. The coding style of this project requires that you add a docstring to this code element. Below, you find an example for methods: class SomeClass: def some_method(self): """Do x and return foo.""" If you would like to know more about docstrings, we recommend to read PEP-257: Docstring Conventions. Loading history...
71		return {
72	1	(k[len('self.'):] if k.startswith('self.') else k): v
73	1	for k, v in pathfields.items()
74		}
75	1
76
77	1	def match(cls_or_path, factory=None, **kwargs):
78		"""match(class, [callable], ...) -> instance, ...
79		match(str, callable, ...) -> instance, ...
80	1
81		Yield all matching mapped objects. Can be used two ways:
82	1	* With a YORM-decorated class, optionally with a factory callable
83		* With a Python 3-style string template and a factory callable
84	1
85		The factory callable must accept keyuword arguments, extracted from the file
86	1	name merged with those passed to match(). If no factory is given, the class
87		itself is used as the factory (same signature).
88		"""
89	1	if isinstance(cls_or_path, type):
90	1	path_format = common.path_formats[cls_or_path]
91	1	# Let KeyError fail through
92		if factory is None:
93	1	factory = cls_or_path
94	1	else:
95		path_format = cls_or_path
96	1	if factory is None:
97		raise TypeError("Factory must be given if a string template is used")
98
99		log.debug((path_format, factory, kwargs))
100		gf = GlobFormatter()
		0 ignored issues – show Coding Style Naming introduced 2017-05-30 19:29 UTC by Report Bug Copy Issue Report The name `gf` does not conform to the variable naming conventions (`[a-z_][a-z0-9_]{2,30}$`). This check looks for invalid names for a range of different identifiers. You can set regular expressions to which the identifiers must conform if the defaults do not match your requirements. If your project includes a Pylint configuration file, the settings contained in that file take precedence. To find out more about Pylint, please refer to their site. Loading history...
101		mock = types.SimpleNamespace(**kwargs)
102
103		kwargs['self'] = mock
104		posix_pattern = gf.vformat(path_format, (), kwargs)
105		py_pattern = parse.compile(path_format)
		0 ignored issues – show Bug introduced 2017-05-30 20:35 UTC by Report Bug Copy Issue Report The Module `parse` does not seem to have a member named `compile`. This check looks for calls to members that are non-existent. These calls will fail. The member could have been renamed or removed. Loading history...
106
107		for filename in glob.iglob(posix_pattern, recursive=False):
		0 ignored issues – show Bug introduced 2017-05-30 19:29 UTC by Report Bug Copy Issue Report The keyword `recursive` does not seem to exist for the function call. Loading history...
108		pathfields = py_pattern.parse(filename).named
109		fields = _unpack_parsed_fields(pathfields)
110		fields.update(kwargs)
111		yield factory(**fields)
		0 ignored issues – show Coding Style introduced 2017-05-30 20:35 UTC by Report Bug Copy Issue Report Usage of `` or `` arguments should usually be done with care. Generally, there is nothing wrong with usage of `` or `**` arguments. For readability of the code base, we suggest to not over-use these language constructs though. For more information, we can recommend this blog post from Ned Batchelder including its comments which also touches this aspect. Loading history...
112
113
114		def load(instance):
115		"""Force the loading of a mapped object's file.
116
117		NOTE: Calling this function is unnecessary. It exists for the
118		aesthetic purpose of having symmetry between save and load.
119
120		"""
121		mapper = common.get_mapper(instance, expected=True)
122
123		mapper.load()
124
125		return instance
126
127
128		def save(instance):
129		"""Save a mapped object to file.
130
131		NOTE: Calling this function is unnecessary with 'auto_save' enabled.
132
133		"""
134		mapper = common.get_mapper(instance, expected=True)
135
136		if mapper.deleted:
137		msg = "{!r} was deleted".format(mapper.path)
138		raise exceptions.DeletedFileError(msg)
139
140		if not mapper.exists:
141		mapper.create()
142
143		mapper.save()
144
145		return instance
146
147
148		def delete(instance):
149		"""Delete a mapped object's file."""
150		mapper = common.get_mapper(instance, expected=True)
151
152		mapper.delete()
153
154		return None
155
156
157		def _instantiate(class_or_instance, args, *kwargs):
		0 ignored issues – show Coding Style introduced 2017-01-24 21:22 UTC by Report Bug Copy Issue Report This function should have a docstring. The coding style of this project requires that you add a docstring to this code element. Below, you find an example for methods: class SomeClass: def some_method(self): """Do x and return foo.""" If you would like to know more about docstrings, we recommend to read PEP-257: Docstring Conventions. Loading history...
158		if inspect.isclass(class_or_instance):
159		instance = class_or_instance(args, *kwargs)
160		else:
161		assert not args
162		instance = class_or_instance
163
164		return instance
165

jacebrowning / yorm

Pull Request — develop (#143)

GlobFormatter.convert_field() A

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