Question

I have a class which hold some variables as strings. e.g.

x = "1"
y = "2.0"
z = "timedelta(seconds=10)"

As you can see above the variables are actually int/float/timedelta-types.
I need to return these variables with their real type. (x should be returned as a int, y should be returned as a float, z should be returned as datetime.timedelta)

I was thinking of changing the getattr and try to find out the type before returning the value, but the small test I did, does not seem to work:

from datetime import datetime, timedelta

def test():
    string = "timedelta(seconds=10)"
    x = eval(string)
    print x
    print type(x)
    if type(x) == 'datetime.timedelta':
        print "YES"
    else:
        print "NO"

The output is:

0:00:10
<type 'datetime.timedelta'>
NO

why is the if-case returning false? is there a better way to return these variables with the real type?

Answer 1

Because type(x) returns type not string. Instead use:

type(x) == datetime.timedelta

# or, the better Python practice

isinstance(x, datetime.timedelta)