sol.models.utils -- Utilities

Simple helper functions.

sol.models.utils.asunicode(s)

Force a string to be a unicode instance.

Parameters

s -- any value

Return type

str

If s is not already an unicode string, it is assumed to be a utf-8 bytes string, and thus decoded to unicode and returned. Otherwise s is returned as is:

>>> assert asunicode(None) is None
>>> assert not isinstance(asunicode(b'ascii'), bytes)

sol.models.utils.normalize(s, title=None)

Normalize the case of a string, removing spurious spaces.

Parameters

• s -- a string

• title -- if True always titleize the string, if False never do that, if None (default) only when the input string is all lower case or all upper case

Return type

unicode

>>> assert normalize(None) is None
>>> print(normalize('lele gaifax'))
Lele Gaifax
>>> print(normalize('LELE'))
Lele
>>> print(normalize('LeLe', title=False))
LeLe

sol.models.utils.njoin(elts, stringify=<function asunicode>, localized=True)

Given a sequence of items, concatenate them in a nice way.

Parameters

• elts -- a sequence of elements

• stringify -- the stringification function applied to all elements, by default coerced to unicode

• localized -- a boolean flag to disable the translation of the final 'and'

Return type

unicode

If elts is empty returns an empty unicode string; if it contains a single element, returns the stringified element; otherwise returns a unicode string composed by all but the last elements stringified and joined by a comma, followed by the localized version of and followed by the last element stringified:

>>> print(njoin([1,2,3]))
1, 2 and 3
>>> print(njoin([1,2]))
1 and 2
>>> print(njoin([1]))
1
>>> assert njoin([]) == ''
>>> print(njoin([1,2], stringify=lambda x: str(x*10)))
10 and 20

Note that falsey elements are skipped:

>>> print(njoin(['first', None, False, '', 'last']))
first and last

but 0 (zero) isn't considered a falsey value:

>>> print(njoin([1,0,2]))
1, 0 and 2

sol.models.utils.entity_from_primary_key(pkname)

Given the name of a primary key, return the mapped entity.

Parameters

pkname -- the name of a primary key

Return type

a mapped class

sol.models.utils.table_from_primary_key(pkname)

Given the name of a primary key, return the related table.

Parameters

pkname -- the name of a primary key

Return type

a SQLAlchemy table