argsloader.units.utils

KeepUnit

class argsloader.units.utils.KeepUnit

Overview:

Unit for keep the original input value.

__init__()

Constructor of class KeepUnit.

keep

argsloader.units.utils.keep() → argsloader.units.utils.KeepUnit

Overview:

Simply keep the original input data.

See KeepUnit.

Returns

A keep unit object.

Examples::

>>> from argsloader.units import keep
>>> u = keep()
>>> u(1)
1
>>> u('this is str')
'this is str'

CheckUnit

class argsloader.units.utils.CheckUnit(unit)

Overview:

Unit for check, the original input data will be kept.

__init__(unit)

Constructor of CheckUnit.

Parameters

unit – Unit used to check.

check

argsloader.units.utils.check(unit) → argsloader.units.utils.CheckUnit

Overview:

Simply keep the input data, the unit is only used for checking.

See CheckUnit.

Parameters

unit – Unit used to check.

Returns

A check unit object.

Examples::

>>> from argsloader.units import check, is_type, add
>>> u = check(is_type(int) >> add.by(2))
>>> u(2)
2
>>> u(10)
10
>>> u(2.0)
TypeParseError: Value type not match - int expected but float found.

ValidityUnit

class argsloader.units.utils.ValidityUnit(unit: argsloader.units.base.BaseUnit)

Overview:

Unit for getting validity of the given unit.

__init__(unit: argsloader.units.base.BaseUnit)

Constructor of ValidityUnit.

Parameters

unit – Unit for getting validity.

validity

argsloader.units.utils.validity(unit) → argsloader.units.utils.ValidityUnit

Overview:

Get the validity of the given unit. Return True when unit is parsed success, otherwise return False.

See ValidityUnit.

Parameters

unit – Unit for getting validity.

Returns

A validity unit object.

Examples::

• Simple usage

>>> from argsloader.units import validity, is_type
>>> u = validity(is_type(int))
>>> u(10)
True
>>> u(10.0)
False

• Attribute-based usage

>>> u = is_type(int).validity  # the same as validity(is_type(int))
>>> u(10)
True
>>> u(10.0)
False

ErrorUnit

class argsloader.units.utils.ErrorUnit(condition, errcls, *args)

Overview:

Unit for raise errors.

__init__(condition, errcls, *args)

Constructor of ErrorUnit.

Parameters

• condition – Condition unit, the error will be raised if condition is satisfied.

• errcls – Error class.

• args – Error arguments.

error

argsloader.units.utils.error(condition, errcls, *args) → argsloader.units.utils.ErrorUnit

Overview:

Raise error when the given condition is satisfied.

Parameters

• condition – Condition unit.

• errcls – Error class.

• args – Error arguments.

Returns

A error unit object.

Examples::

>>> from argsloader.units import error, is_type
>>> u = error(is_type(int).validity, KeyError, 'a key error')
>>> u(10.0)
10.0
>>> u(10)
KeyParseError: 'a key error'

validate

argsloader.units.utils.validate(val, condition, errcls, *args)

Overview:

Raise error based on the validation of data.

Parameters

• val – Data calculation unit.

• condition – Validation unit, the error will be raised if this condition is not satisfied.

• errcls – Error class.

• args – Error arguments.

Returns

A unit object which can do the validation.

Examples::

>>> from argsloader.units import to_type, le, validate
>>> u = validate(to_type(int), le.than(5).validity, KeyError, 'a key error')
>>> u(4)
4
>>> u(5.2)
5.2
>>> u(6.0)
KeyParseError: 'a key error'

fail

argsloader.units.utils.fail(errcls, *args) → argsloader.units.utils.ErrorUnit

Overview:

Raise error at any time.

Parameters

• errcls – Error class.

• args – Error arguments.

Returns

A unit object which can raise error.

Examples::

>>> from argsloader.units import fail
>>> u = fail(KeyError, 'a key error')
>>> u(1)
KeyParseError: 'a key error'

IfUnit

class argsloader.units.utils.IfUnit(statements: List[Tuple[argsloader.units.base.BaseUnit, argsloader.units.base.BaseUnit]])

Overview:

Unit for if statement.

__init__(statements: List[Tuple[argsloader.units.base.BaseUnit, argsloader.units.base.BaseUnit]])

Constructor of IfUnit.

Parameters

statements – If statements.

_IfProxy

class argsloader.units.utils._IfProxy(statements)

Overview:

If proxy object, used to build IfUnit.

elif_(cond, val) → argsloader.units.utils._IfProxy

Add an else-if clause.

Parameters

• cond – Condition unit.

• val – Value unit.

Returns

Another _IfProxy with this new else-if clause.

else_(val) → argsloader.units.utils.IfUnit

Add an else clause.

Parameters

val – Value unit.

Returns

A completed IfUnit with this else clause.

if_

argsloader.units.utils.if_(cond, val) → argsloader.units.utils._IfProxy

Overview:

If clause to determine the return value.

Parameters

• cond – Condition unit.

• val – Value unit.

Returns

An initial _IfProxy unit, a full if statement will be built based on this.

Examples::

>>> from argsloader.units import if_, is_type
>>> u = if_(is_type(int).validity, 'an int').elif_(is_type(float).validity, 'a float').else_('fxxk off')
>>> u(1)
'an int'
>>> u(1.0)
'a float'
>>> u('1')
'fxxk off'