whitematteranalysis.utils package#

Subpackages#

Submodules#

whitematteranalysis.utils.opt_pckg module#

Methods to support optional packages.

whitematteranalysis.utils.opt_pckg.optional_package(name, trip_msg=None)#

Return package-like thing and module setup for package name.

namestr
Package name.

trip_msgNone or str
Message to be shown when the specified package cannot be imported.

pckgpackage, module or TripWire instance
If the package can be imported, return it. Otherwise, return an object raising an error when accessed.

have_pkgbool
True if import for package was successful, False otherwise.

module_setupfunction
Callable usually set as setup_module in calling namespace, to allow skipping tests.

Typical use:
>>> from whitematteranalysis.utils.opt_pckg import optional_package
>>> pckg, have_pckg, _setup_module = optional_package("not_a_package")

In this case the package doesn’t exist, and therefore:

>>> have_pckg
False

and

>>> pckg.some_function() 
Traceback (most recent call last):
    ...
TripWireError: We need package not_a_package for these functions, but
``import not_a_package`` raised an ImportError

If the module does exist - we get the module

>>> pckg, _, _ = optional_package("os")
>>> hasattr(pckg, "path")
True

Or a submodule if that’s what we asked for

>>> subpckg, _, _ = optional_package("os.path")
>>> hasattr(subpckg, "dirname")
True

whitematteranalysis.utils.tripwire module#

class whitematteranalysis.utils.tripwire.TripWire(msg)#

Bases: object

Class raising error if used.

Standard use is to proxy modules that could not be imported.

Examples

>>> try:
...     import not_a_package
... except ImportError:
...    not_a_package_name = TripWire("Do not have not_a_package_name")
>>> not_a_package_name.do_something("with argument") 
Traceback (most recent call last):
    ...
TripWireError: Do not have not_a_package_name

exception whitematteranalysis.utils.tripwire.TripWireError#

Bases: AttributeError

Class to raise an exception for missing modules or other misfortunes..

whitematteranalysis.utils.tripwire.is_tripwire(obj)#

Returns True if obj appears to be a TripWire object.