GlobFormatter.format_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 19:06 UTC

GlobFormatter.format_field() A

↳ Parent: GlobFormatter

Complexity

Conditions

Size

Total Lines

Duplication

Lines	0
Ratio	0 %

Code Coverage

Tests	1
CRAP Score	2

Importance

Changes

Metric	Value
c	0
b	0
f	0
dl	0
loc	5
ccs	1
cts	1
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)

    posix_pattern = gf.format(path_format, self=mock, **kwargs)

    py_pattern = parse.compile(path_format)


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

        pathfields = py_pattern.parse(filename)
        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		posix_pattern = gf.format(path_format, self=mock, **kwargs)
		0 ignored issues – show Unused Code introduced 2017-05-30 20:35 UTC by Report Bug Copy Issue Report Argument 'self' passed by position and keyword in method call Loading history...
104		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...
105
106		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...
107		pathfields = py_pattern.parse(filename)
108		fields = _unpack_parsed_fields(pathfields)
109		fields.update(kwargs)
110		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...
111
112
113		def load(instance):
114		"""Force the loading of a mapped object's file.
115
116		NOTE: Calling this function is unnecessary. It exists for the
117		aesthetic purpose of having symmetry between save and load.
118
119		"""
120		mapper = common.get_mapper(instance, expected=True)
121
122		mapper.load()
123
124		return instance
125
126
127		def save(instance):
128		"""Save a mapped object to file.
129
130		NOTE: Calling this function is unnecessary with 'auto_save' enabled.
131
132		"""
133		mapper = common.get_mapper(instance, expected=True)
134
135		if mapper.deleted:
136		msg = "{!r} was deleted".format(mapper.path)
137		raise exceptions.DeletedFileError(msg)
138
139		if not mapper.exists:
140		mapper.create()
141
142		mapper.save()
143
144		return instance
145
146
147		def delete(instance):
148		"""Delete a mapped object's file."""
149		mapper = common.get_mapper(instance, expected=True)
150
151		mapper.delete()
152
153		return None
154
155
156		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...
157		if inspect.isclass(class_or_instance):
158		instance = class_or_instance(args, *kwargs)
159		else:
160		assert not args
161		instance = class_or_instance
162
163		return instance
164

jacebrowning / yorm

Pull Request — develop (#143)

GlobFormatter.format_field() A

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