I have a string in the following form :
"425x344"
Now I'd like to resolve first and second numbers from this string as two separate variables. How can I do this ? I've created this regex:
regex = re.compile(r"^(\d+x\d+)")
to check if the string form is proper. But what next ?
a, b = '425x344'.split('x')
int, str and the other builtin class constructors are one of the few cases where map is better than a list comprehension. The more you know.Since you're filtering it with a regex, you can just do
a, b = map(int, s.split('x'))
res = a * b
If you're planning on multiplying, it can be done in one line:
res = eval(s.replace('x', '*'))
or
res = (lambda x, y: x * y)(*map(int, s.split('x')))
With an import and one line, this can be done with
import operator
res = operator.mul(*map(int, s.split('x')))
You'll have to profile them to see which is faster.
Syntax Error: invalid syntaxChange it to:
regex = re.compile(r"^(\d+)x(\d+)")
Then use regex.match(my_string) to get the MatchObject out, and you can use match.group(1) and match.group(2) to get the variables out.
group(0) returns the full match text. You want group(1) and group(2).You probably mean "values", or "literals". 425 is not typically a valid name for a variable, which tend to have symbolic names.
If you change your regular expression to capture the numbers separately:
regex = re.compile(r"^(\d+)x(\d+)")
you can then use code like this:
str = "425x344"
mo = regex.search(str)
if mo != None:
print "%s=%d" % (str, int(mo.group(1)) * int(mo.group(2)))
to compute the result.
If you are wanting to do it with re, http://effbot.org/zone/xml-scanner.htm might be worth a read. It shows how to properly split each argument in a expr with re
import re
expr = "b = 2 + a*10"
for item in re.findall("\s*(?:(\d+)|(\w+)|(.))", expr):
print item
...$and.match(or^...$and.search) to make sure the whole sting is consumed. As of now, both ways of running the regex accept1x1foo.$will accept1x1\n