implicitly concats of adjacent strings does not work with format

Mark Lawrence breamoreboy at yahoo.co.uk
Wed Apr 29 18:04:49 CEST 2015


On 29/04/2015 15:40, Cecil Westerhof wrote:
> Op Wednesday 29 Apr 2015 15:14 CEST schreef Dave Angel:
>
>> On 04/29/2015 08:42 AM, Cecil Westerhof wrote:
>>> I have the folowing print statements:
>>> print(
>>> 'Calculating fibonacci_old, fibonacci_memoize and'
>>> 'fibonacci_memoize once for {0} '.format(large_fibonacci))
>>>
>>>
>>> print(
>>> 'Calculating fibonacci_old, fibonacci_memoize and'
>>> 'fibonacci_memoize once for {0} '.format(large_fibonacci) +
>>> 'to determine speed increase')
>>>
>>> print(
>>> 'Calculating fibonacci_old, fibonacci_memoize and'
>>> 'to determine speed increase'
>>> 'fibonacci_memoize once for {0} '.format(large_fibonacci))
>>>
>>>
>>> print(
>>> 'Calculating fibonacci_old, fibonacci_memoize and'
>>> 'fibonacci_memoize once for {0} '.format(large_fibonacci)
>>> 'to determine speed increase')
>>>
>>> The first three work, but the last gives:
>>> 'to determine speed increase')
>>> ^
>>> SyntaxError: invalid syntax
>>>
>>> Not very important, because I can use the second one, but I was
>>> just wondering why it goes wrong.
>>>
>>
>> Adjacent string literals are concatenated. But once you've called a
>> method (.format()) on that literal, you now have an expression, not
>> a string literal.
>>
>> You could either change the last line to
>>
>> + 'to determine speed increase')
>>
>> or you could concatenate all the strings before calling the format
>> method:
>>
>>
>> print(
>> 'Calculating fibonacci_old, fibonacci_memoize and'
>> 'fibonacci_memoize once for {0}'
>> 'to determine speed increase' .format(large_fibonacci))
>
> I now use this, I did not know that the addjacent-concatenation
> occurred at compile time.
> I spend a ‘little‘ time, but it was worth it.
>
>  From the amount of messages you could think I am a spammer. ;-)
>

Did you mean spanner? ;-)

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence




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