On 05/03/2023 22:59, aapost wrote:
On 3/5/23 17:43, Stefan Ram wrote:
The following behaviour of Python strikes me as being a bit
"irregular". A user tries to chop of sections from a string,
but does not use "split" because the separator might become
more complicated so that a regular expression will be required
to find it. But for now, let's use a simple "find":
|>>> s = 'alpha.beta.gamma'
|>>> s[ 0: s.find( '.', 0 )]
|'alpha'
|>>> s[ 6: s.find( '.', 6 )]
|'beta'
|>>> s[ 11: s.find( '.', 11 )]
|'gamm'
|>>>
. The user always inserted the position of the previous find plus
one to start the next "find", so he uses "0", "6", and "11".
But the "a" is missing from the final "gamma"!
And it seems that there is no numerical value at all that
one can use for "n" in "string[ 0: n ]" to get the whole
string, isn't it?
The final `find` returns -1 because there is no separator after 'gamma'.
So you are asking for
s[ 11 : -1]
which correctly returns 'gamm'.
You need to test for this condition.
Alternatively you could ensure that there is a final separator:
s = 'alpha.beta.gamma.'
but you would still need to test when the string was exhausted.
Best wishes
Rob Cliffe
--
https://mail.python.org/mailman/listinfo/python-list
