Utils¶

django_docker_helpers.utils._materialize_dict(bundle, separator='.')[source]¶

Traverses and transforms a given dict bundle into tuples of (key_path, value).

Parameters

bundle (dict) – a dict to traverse
separator (str) – build paths with a given separator

Return type

Generator[Tuple[str, Any], None, None]

Returns

a generator of tuples (materialized_path, value)

Example: >>> list(_materialize_dict({‘test’: {‘path’: 1}, ‘key’: ‘val’}, ‘.’)) >>> [(‘key’, ‘val’), (‘test.path’, 1)]

django_docker_helpers.utils.coerce_str_to_bool(val, strict=False)[source]¶

Converts a given string val into a boolean.

Parameters

val (Union[str, int, None]) – any string representation of boolean
strict (bool) – raise ValueError if val does not look like a boolean-like object

Return type

bool

Returns

True if val is thruthy, False otherwise.

Raises

ValueError – if strict specified and val got anything except ['', 0, 1, true, false, on, off, True, False]

django_docker_helpers.utils.dot_path(obj, path, default=None, separator='.')[source]¶

Provides an access to elements of a mixed dict/object type by a delimiter-separated path.

class O1:
    my_dict = {'a': {'b': [1, 2]}}

class O2:
    def __init__(self):
        self.nested = O1()

class O3:
    final = O2()

o = O3()
assert utils.dot_path(o, 'final.nested.my_dict.a.b.1') == 2

True

Parameters

obj (object) – object or dict
path (str) – path to value
default (Optional[Any]) – default value if chain resolve failed
separator (str) – . by default

Returns

value or default

django_docker_helpers.utils.dotkey(obj, path, default=None, separator='.')[source]¶

Provides an interface to traverse nested dict values by dot-separated paths. Wrapper for dpath.util.get.

Parameters

obj (dict) – dict like {'some': {'value': 3}}
path (str) – 'some.value'
separator – '.' or '/' or whatever
default – default for KeyError

Returns

dict value or default value

django_docker_helpers.utils.env_bool_flag(flag_name, strict=False, env=None)[source]¶

Converts an environment variable into a boolean. Empty string (presence in env) is treated as True.

Parameters

flag_name (str) – an environment variable name
strict (bool) – raise ValueError if a flag_name value connot be coerced into a boolean in obvious way
env (Optional[Dict[str, str]]) – a dict with environment variables, default is os.environ

Return type

bool

Returns

True if flag_name is thruthy, False otherwise.

Raises

ValueError – if strict specified and val got anything except ['', 0, 1, true, false, True, False]

django_docker_helpers.utils.env_tristate_flag(flag_name, strict=False, env=None)[source]¶

Converts an environment variable into a boolean or None if not present. Empty string (presence in env) is treated as True.

Parameters

flag_name (str) – an environment variable name
strict (bool) – raise ValueError if a flag_name value connot be coerced into a boolean in obvious way
env (Optional[Dict[str, str]]) – a dict with environment variables, default is os.environ

Return type

Optional[bool]

Returns

True if flag_name is thruthy, False otherwise.

Raises

ValueError – if strict specified and val got anything except ['', 0, 1, true, false, True, False]

django_docker_helpers.utils.is_dockerized(flag_name='DOCKERIZED', strict=False)[source]¶

Reads env DOCKERIZED variable as a boolean, or detects docker.

Parameters

flag_name (str) – environment variable name
strict (bool) – raise a ValueError if variable does not look like a normal boolean

Return type

bool

Returns

True if has truthy DOCKERIZED env, False otherwise

django_docker_helpers.utils.is_production(flag_name='PRODUCTION', strict=False)[source]¶

Reads env PRODUCTION variable as a boolean.

Parameters

flag_name (str) – environment variable name
strict (bool) – raise a ValueError if variable does not look like a normal boolean

Return type

bool

Returns

True if has truthy PRODUCTION env, False otherwise

django_docker_helpers.utils.materialize_dict(bundle, separator='.')[source]¶

Transforms a given bundle into a sorted list of tuples with materialized value paths and values: ('path.to.value', <value>). Output is ordered by depth: the deepest element first.

Parameters

bundle (dict) – a dict to materialize
separator (str) – build paths with a given separator

Return type

List[Tuple[str, Any]]

Returns

a depth descending and alphabetically ascending sorted list (-deep, asc), the longest first

sample = {
    'a': 1,
    'aa': 1,
    'b': {
        'c': 1,
        'b': 1,
        'a': 1,
        'aa': 1,
        'aaa': {
            'a': 1
        }
    }
}
materialize_dict(sample, '/')
[
    ('b/aaa/a', 1),
    ('b/a', 1),
    ('b/aa', 1),
    ('b/b', 1),
    ('b/c', 1),
    ('a', 1),
    ('aa', 1)
]

django_docker_helpers.utils.mp_serialize_dict(bundle, separator='.', serialize=<function dump>, value_prefix='::YAML::\\n')[source]¶

Transforms a given bundle into a sorted list of tuples with materialized value paths and values: ('path.to.value', b'<some>'). If the <some> value is not an instance of a basic type, it’s serialized with serialize callback. If this value is an empty string, it’s serialized anyway to enforce correct type if storage backend does not support saving empty strings.

Parameters

bundle (dict) – a dict to materialize
separator (str) – build paths with a given separator
serialize (Optional[Callable]) – a method to serialize non-basic types, default is yaml.dump
value_prefix (str) – a prefix for non-basic serialized types

Return type

List[Tuple[str, bytes]]

Returns

a list of tuples (mat_path, b'value')

sample = {
    'bool_flag': '',  # flag
    'unicode': 'вася',
    'none_value': None,
    'debug': True,
    'mixed': ['ascii', 'юникод', 1, {'d': 1}, {'b': 2}],
    'nested': {
        'a': {
            'b': 2,
            'c': b'bytes',
        }
    }
}

result = mp_serialize_dict(sample, separator='/')
assert result == [
    ('nested/a/b', b'2'),
    ('nested/a/c', b'bytes'),
    ('bool_flag', b"::YAML::\n''\n"),
    ('debug', b'true'),
    ('mixed', b'::YAML::\n- ascii\n- '
              b'"\\u044E\\u043D\\u0438\\u043A\\u043E\\u0434"\n- 1\n- '
              b'{d: 1}\n- {b: 2}\n'),
    ('none_value', None),
    ('unicode', b'\xd0\xb2\xd0\xb0\xd1\x81\xd1\x8f')
]

django_docker_helpers.utils.run_env_once(f)[source]¶

A decorator to prevent manage.py from running code twice for everything. (https://stackoverflow.com/questions/16546652/why-does-django-run-everything-twice)

Parameters: f (Callable) – function or method to decorate
Return type: Callable
Returns: callable

django_docker_helpers.utils.shred(key_name, value, field_names=('password', 'secret', 'pass', 'pwd', 'key', 'token', 'auth', 'cred'))[source]¶

Replaces sensitive data in value with * if key_name contains something that looks like a secret.

Parameters

field_names (Iterable[str]) – a list of key names that can possibly contain sensitive data
key_name (str) – a key name to check
value (Any) – a value to mask

Return type

Union[Any, str]

Returns

an unchanged value if nothing to hide, '*' * len(str(value)) otherwise

django_docker_helpers.utils.wf(raw_str, flush=True, prevent_completion_polluting=True, stream=<_io.TextIOWrapper name='<stdout>' mode='w' encoding='UTF-8'>)[source]¶

Writes a given raw_str into a stream. Ignores output if prevent_completion_polluting is set and there’s no extra sys.argv arguments present (a bash completion issue).

Parameters

raw_str (str) – a raw string to print
flush (bool) – execute flush()
prevent_completion_polluting (bool) – don’t write anything if len(sys.argv) <= 1
stream (TextIO) – sys.stdout by default

Returns

None