/prog/ - Programming

Gimme some sources to learn python

>>5190

https://docs.python.org/3/tutorial/index.html

Hey, I'm learning Python, specifically Python 3.6. I came across an issue involving tuples, specifically with:

tuple.index(x)

Whenever x is a variable defined by an input, it gives me a value error saying it is not in the tuple. Is there some work-around?

I can provide the original code and error message as needed.

>>50378

if i remember then input is a string and needs to be convertet to an int if you want to use it with index

>>5378

https://docs.python.org/3/library/stdtypes.html#index-19

"""8. index raises ValueError when x is not found in s. Not all implementations support passing the additional arguments i and j. These arguments allow efficient searching of subsections of the sequence. Passing the extra arguments is roughly equivalent to using s[i:j].index(x), only without copying any data and with the returned index being relative to the start of the sequence rather than the start of the slice."""

While this is poor design, it is documented behavior. The workaround is:

>>> import operator
>>> import functools
>>> def seqindex (seq, item):
...    return next (
...       map       (operator.itemgetter (0),
...       filter    (operator.itemgetter (1),
...       enumerate (
...       map       (functools.partial (operator.eq, item),
...       seq)))), -1)
... 
>>> seqindex ((1, 2, 3), 3)
2
>>> seqindex ((1, 2, 3), 4)
-1
>>> 

>>5378

OP here, fixed the code, works fine now. I appreciate the help.

>>5378

Was it a type thing? Did you have a tuple with integers in it, nad were trying to find the index using a string variable?