Dynamically import matplotlib.pyplot

[yuyu2172]

Related chainer/chainer#2740

matplotlib backend can now be configured after importing chainercv.

[knorth55]

@yuyu2172 How about also importing matplotlib in the position of _check_available()?

class Hogehoge():
    def __init__():
         try:
            import matplotlib
            self.pyplot = matplotlib.pyplot
         except:
             warn('hogehoge')

[yuyu2172]

Why do we need to have a module matplotlib.pyplot as an attribute?

[knorth55]

i thought the problem is importing the module multiple times.
In that case, i thought its better keeping the module as attribute and reusing it

[Hakuyume]

Are there any cases that TypeError is raised?

[yuyu2172]

I copied it from Chainer.

TypeError is sometimes called when backend is not imported properly.

related

chainer/chainer#2482

https://stackoverflow.com/questions/31328436/typeerror-constructor-returned-null-while-importing-pyplot-in-ssh

[Hakuyume]

I see.

[Hakuyume]

I don't think keeping a module as an attribute is good. @yuyu2172's solution looks good and enough.

[Hakuyume]

LGTM