I have numerical values that are loaded from a JSON object and are therefore all strings.
I am having issues with making numerical comparisons with these strings. The following makes no sense to me and I was hoping one of you champions could explain..
In[2]: print '100' < '45'
True
In[3]: print '99' < '45'
False
Using Python 2.7
When comparing strings they're compared by the ascii value of the characters. '1' has a value 49, and '4' is 52. So '1' is < '4'. '9' however is 57, so '9' is > '4'.
If you want to compare them numerically you could just int() the strings first like:
print int('100') < int('45')
float, although I had to account for nan with an if loop because the JSON parser on the client side (Chrome) was throwing an error with NaN, I had to replace NaN with None (see stackoverflow.com/questions/15228651/…)It basically checks for lexicographic ordering. Check documentation here -
>>> 'b' <'a'
False
>>> 'a' < 'b'
True
In above example, a comes before b, hence 'a' <'b' is true. But, not vica versa. Similarly '1'<'2'.
Hence '199999999999' < '5' is true because 1 comes before 5.
'1999' < '5'. edited in the answer. Thanks @AlokThakur