[Tutor] how to unittest cli input

[Peter Otten]

Alex Kleider wrote:

> On 2015-10-14 12:27, Peter Otten wrote:
>> Alex Kleider wrote:
>> 
>>> On 2015-10-13 14:44, Alex Kleider wrote:
>>>> On 2015-10-13 12:11, Danny Yoo wrote:
>>>> 
>>>> 
>>>>> ######################
>>>>> def make_ask(f, l, p):
>>>>>     d = {'Enter your first name: ' : f,
>>>>>            'Enter your last name: ' : l,
>>>>>            'Your mobile phone #: ' : p}
>>>>>     return d.get
>>>>> ######################
>>> 
>>> This is an example of a 'closure' is it not?
>> 
>> It does not make big difference, but I would call the return value
>> "bound
>> method" rather than "closure". For me closure implies access to the
>> local
>> namespace of the enclosing function, e. g.
>> 
>> def make_ask(f, l, p):
>>     d = {'Enter your first name: ' : f,
>>            'Enter your last name: ' : l,
>>            'Your mobile phone #: ' : p}
>>     def get(key):
>>         return d.get(key)
>>     return get
>> 
>> Here d is looked up when get() is invoked. Let's make a modification to
>> demonstrate that the current binding of d is used:
>> 
>>>>> def make_ask(f, l, p):
>> ...     d = {'Enter your first name: ' : f,
>> ...            'Enter your last name: ' : l,
>> ...            'Your mobile phone #: ' : p}
>> ...     def get(key):
>> ...         return d.get(key)
>> ...     def set_d(new_d):
>> ...         nonlocal d
>> ...         d = new_d
>> ...     return get, set_d
>> ...
>>>>> get, set_d = make_ask(*"abc")
>>>>> get("Enter your first name: ")
>> 'a'
>>>>> class WontTell:
>> ...     def get(self, key): return "won't tell"
>> ...
>>>>> set_d(WontTell())
>>>>> get("Enter your first name: ")
>> "won't tell"
> 
> Thank you, Peter, for your continued efforts to explain.
> It is all getting pretty convoluted for my poor brain!
> It took a very long time for me to figure out what the
> class WontTell was all about.

Sorry about that digression. The example would work with any old dict

>>> get, set_d = make_ask("John", "Doe", "123")
>>> get("Enter your last name: ")
'Doe'
>>> set_d({"foo": "bar"})
>>> get("Enter your last name: ") is None
True
>>> get("foo")
'bar'

but that way the effect of rebinding d (which is what happens) is the same 
as replacing the data in the dict initially bound to d.

> I probably should follow Danny Yoo's advice and not concern
> myself with this but my curiosity is roused.