Hi,
I am extremely new to python, and I am completely stuck regarding filtering the contents of a list. I have a list of the first thirty elements, and i have been told to identify any beginning with the letter 's' and any that are four letters long. I have already inputted the list.
Could you give me a link to an example or tell me the function to use please.
Thanks.
Most natural way is list comprehesion.
http://www.pythonforbeginners.com/lists/list-comprehensions-in-python/
Start by testing stuff out in interactive interpreter.
>>> lst = ['This', 'is' 'some', 'test', 'of', 'someting']
>>> lst[0]
'This'
>>> len(lst[0])
4
So useful for finding 4 letters word.
Basic iterate over a list.
>>> lst = ['This', 'is', 'some', 'test', 'of', 'someting']
>>> for item in lst:
... print(item)
...
This
is
some
test
of
someting
>>> for item in lst:
... if len(item) == 4:
... print(item)
...
This
some
test
>>> [item for item in lst if len(item) == 4]
['This', 'some', 'test']
Same for finding letter beginning "s" iterate over with startswith() method.
What "startswith" dos,the name pretty much reveale it.help() works fine.
>>> help(str.startswith)
Help on method_descriptor:
startswith(...)
S.startswith(prefix[, start[, end]]) -> bool
Return True if S starts with the specified prefix, False otherwise.
With optional start, test S beginning at that position.
With optional end, stop comparing S at that position.
prefix can also be a tuple of strings to try.
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