python float to in int conversion

Question

I have an issue that really drives me mad. Normally doing int(20.0) would result in 20 . So far so good. But:

levels = [int(gex_dict[i]) for i in sorted(gex_dict.keys())]

while gex_dict[i] returns a float, eg 20.0 , results in:

"invalid literal for int() with base 10: '20.0'"

I am just one step away from munching the last piece of my keyboard.

Answer 1

'20.0' is a string, not a float ; you can tell by the single-quotes in the error message. You can get an int out of it by first parsing it with float , then truncating it with int :

>>> int(float('20.0'))
20

(Though maybe you'd want to store floats instead of strings in your dictionary, since that is what you seem to be expecting.)

Answer 2

It looks like the value is a string, not a float. So you need int(float(gex_dict[i]))

Answer 3

It looks like the problem is that gex_dict[i] actually returns a string representation of a float '20.0' . Although int() has the capability to cast from a float to an int, and a string representation of an integer to an int. It does not have the capability to cast from a string representation of a float to an int.

The documentation for int can be found here: http://docs.python.org/library/functions.html#int

Answer 4

The problem is that you have a string and not a float, see this as comparison:

>>> int(20.0)
20
>>> int('20.0')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: invalid literal for int() with base 10: '20.0'

You can workaround this problem by first converting to float and then to int:

>>> int(float('20.0'))
20

So it would be in your case:

levels = [int(float(gex_dict[i])) for i in sorted(gex_dict.keys())]