[Tutor] Problems understanding control flow

[Eduardo Vieira]

On Thu, Jul 30, 2009 at 4:49 PM, Sander Sweers<sander.sweers at gmail.com> wrote:
> 2009/7/30 Eduardo Vieira <eduardo.susan at gmail.com>:
>
> With == you are testing if the 2 values are exactly the same. So 'one'
> == 'one' will return True but 'one; == 'one two' will return False.
>
> With in you test if the value is part of a another value. So using the
> same value as above 'one' in 'one' will return True but 'one' in 'one
> two' will also return True as 'one' is part of the second string.
>
> The same logic applies to lists and dicts. 'one' == ['one', 'two']
> will return False as the the 2 values are not exactly the same but
> 'one' in ['one', 'two'] will return True.
>
>> # this does not work:
>> for row in sitelist:
>>   for line in bvreaderone:
>
> If you are getting unexpected results add in print statements to see
> what is the data that you are working with. I would add the below 2
> print statements to see what you are now actually comparing. Same
> applies to the other working example.
> :
>    print 'Value row['EMAIL'] is: %s' % row['EMAIL']
>    print 'Value of line['BVADDREMAIL'] is: %s' % line['BVADDREMAIL']
>
>>       if row['EMAIL'] == line['BVADDREMAIL']:
>
> Here you are testing if the value of row['EMAIL'] is exactly the same
> as line['BVADDREMAIL']: which is not the case so the test returns
> False and the below print statement is not executed.
>
>>           print line['NAME'], row['COMPANY']
>>
>> # but this does work:
>> for row in sitelist:
>>   for line in bvreaderone:
>>       if row['EMAIL'] in line['BVADDREMAIL']:
>
> Here you test if the value row['E_MAIL'] is part of
> line['BVADDREMAIL']:which is True.
>
>>           print line['NAME'], row['COMPANY']
>
> Someone did a way better job writing this down some time a go but
> can't find the post online. I hope you see now what the difference is
> between the 2.
Thanks for pointing out this, Sander. Yes, a print statement revealed
the right after commas... In this case I should enable the option from
the csv module to ignore such white spaces.

Eduardo