[Tutor] string to integer
alan.gauld at freenet.co.uk
Thu Jan 5 23:16:44 CET 2006
> Here is how it should work:
> val(7) = 7
> val(bbab7) = 7
> val(aa7aa) = 7
> val( 7) = 7
There is no direct equivalent for val() as shpwn above the
nearest is int() or float() but that will only work with the first
and last examples. (It is a pretty arbitrary functionn to convert
aa7aa to 7!)
What does val do with a6b5c?
You could strip all chars out of the string first:
nums = [ch for ch in aString if ch in string.digits]
val = int(str(nums))
Which would result in 65 for the example I gave... and
that might be what you expect?
> This last is most important, currently I don't know how to
> convert string " 7" to integer value 7 in my program
Just use int()
> Also, what are chr() values for enter and (empty) space ?
Why would you need chr if you know its an empty space?
Just use ' ' directly.
if ch = ' ':....
'enter' is more tricky since it depends on your OS and to
some extent your terminal type. For example a TekTronics
terminal in an xterm window on Linux gives a different value
for Enter than the default vt100 terminal...
Again, if we knew why you needed to know we might be able
to suggest a suitable mechanism otr alternate technique?
> If anybody have a table with chr() values, I'd appreciate
> if he upload it somewhere.
Just do a google search for ASCII that should find several
tables of the value/character combinations. Searching for
Unicode will likewise find the Unicode values.
chr() is just the string representation of a number.
n = ord(c)
should print c since ord() convers the character to a number
and chr() converts it back...
for n in range(256): print chr(n)
will print all of them (although some are unprintable!)
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