I'm new with python and regular expressions.
I have this regular expressions and i don't know what is the purpose of this
r'(\d+)\.(\d*)'
all I know is it matches a digit from 0 to 9.
can anyone help me explain it?
thanks..
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3Take a look at the docs.Lev Levitsky– Lev Levitsky2012-05-20 14:47:16 +00:00Commented May 20, 2012 at 14:47
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3 Answers
It matches a string containing one or more decimal digits, followed by a decimal place, followed by 0 or more decimal digits - ie, a floating-point number. It returns the two strings of digits.
For example, if you try it on the string "123.456" it will return ("123", "456").
2 Comments
Junuxx
It's kind of strange though that although it allows numbers with zero decimals, the dot is required. I think
r'(\d+)\.?(\d*)' would make more sense to catch floats.
Hugh Bothwell
(shrug) it matches python syntax; 0 is int, 0. is float.
This looks for at least one digit (or more) followed by a decimal point and zero or more digits after it.
This quick reference/cheat sheet might be helpful looking up the parts that make up regular expressions.
This is a very nice Google video tutorial on regular expressions.
Comments
http://docs.python.org/library/re.html read it up. It will definitely be more enlightening than any answer you get here. That though matches digits (1 or more) followed by a decimal point and some further numbers (0 or more)
