How can I check if a string has a numeric value in it in Python? [duplicate]

问题

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Closed 7 years ago.

Possible Duplicate:
How do I check if a string is a number in Python?
Python - Parse String to Float or Int

For example, I want to check a string and if it is not convertible to integer(with int()), how can I detect that?

回答1:

Use the .isdigit() method:

>>> '123'.isdigit()
True
>>> '1a23'.isdigit()
False

Quoting the documentation:

Return true if all characters in the string are digits and there is at least one character, false otherwise.

For unicode strings or Python 3 strings, you'll need to use a more precise definition and use the unicode.isdecimal() / str.isdecimal() instead; not all Unicode digits are interpretable as decimal numbers. U+00B2 SUPERSCRIPT 2 is a digit, but not a decimal, for example.

回答2:

You can always try it:

try:
   a = int(yourstring)
except ValueError:
   print "can't convert"

Note that this method outshines isdigit if you want to know if you can convert a string to a floating point number using float

来源：https://stackoverflow.com/questions/12466061/how-can-i-check-if-a-string-has-a-numeric-value-in-it-in-python