quick, simple type conversion question

[kjm1102]

I can convert an integer (eg 0x32) to a string ('0x32') easily

>>> i=0x32; s=str(i); print(repr(i), type(i), repr(s), type(s))
50 <class 'int'> '50' <class 'str'>

but I can't think of a way to do the reverse, ie change '0x32' into 0x32. Curious if someone knows how?

[andrewleech]

There's a few ways but these are the first ways I thought of to convert both directions

>>> i = 0x32
>>> i
50
>>> hex(i)
'0x32'
>>> int('0x32', 0)
50

[jimmo]

Yep this is the best way. The 0 is a bit magical here, it means "detect the base". You can also explicitly do int('0x32', 16) which will fail if it doesn't start with "0x".

[andrewleech]

Or if you want to convert decimal instead of hex:

>>> int('50', 0)
50
>>> int('50', 10)
50

[steveh127]

Or simply int('0x32') no need for the 0 or 16. The conversion is simple in either direction.

[kjm1102]

When I convert integer to string upython throws in a hex-to-decimal conversion for both types

>>> i=0x32; s=str(i); print(repr(i), type(i), repr(s), type(s))
50 <class 'int'> '50' <class 'str'>

but when I convert string to integer

>>> s='0x32'; i=int(s); print(repr(s), type(s), repr(i), type(i))
'0x32' <class 'str'> 50 <class 'int'>

I only get the hex-to-decimal conversion for one of the types. Does anyone know why that is?

[andrewleech]

An integer number doesn't have a hex or decimal conversion, a number is just a number. It's only the display of the number that can be in hex or decimal form, the number itself is always the same.

If you want to display an integer in hex (string) form, you can use the hex(i) function I used in my first example.

[robert-hh]

Your code asks python to print a string, and that is done. By chance, this string represents a hex number, but it could as well be any text.