Best way to see if a number is fractional or not

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Category:Languages

I'm looking to differentiate between a number like 2.0 or 2 and an actual fractional number such as 2.4. What would be the best way to do this? Currently I'm doing:

def is_fractional(num):     if not str(num).replace('.','').isdigit(): return     return float(num) != int(num)  >>> is_fractional(2) False >>> is_fractional(2.1) True >>> is_fractional(2.0) False >>> is_fractional('a') >>> 

 


That operation is built-in:

>>> 5.0.is_integer() True >>> 5.00000001.is_integer() False >>> 4.9999999.is_integer() False 

Documentation is here.

ADDENDUM

The initial solution only works for float. Here's a more complete answer, with tests:

from decimal import Decimal  def is_integer(x):     if isinstance(x, int):         return True     elif isinstance(x, float):         return x.is_integer()     elif isinstance(x, Decimal):         return x.as_integer_ratio()[1] == 1     return False  good = [     0,      0.0,      3,      -9999999999999999999999,      -2.0000000000000,     Decimal("3.000000"),     Decimal("-9") ] bad = [     -9.99999999999999,     "dogs",     Decimal("-4.00000000000000000000000000000000001"),     Decimal("0.99999999999999999999999999999999999") ]  for x in good:     assert is_integer(x) for x in bad:     assert not is_integer(x) print("All tests passed") 

Comment

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