[Tutor] How can I convert hex string to binary string?

[Scot Stevenson]

Hello Ares, 

> such as '0A0B' to '0000101000001011' ?
> is there any function or module?

If I remember my binary math, each hex numeral (0 to F, that is) has an 
equivalent four digit binary number (0000 to 1111), so that

Hex - Bin

0	0000
2	0010
3	0011
...
E	1110
F	1111

So all you should have to do is a) make a dictionary with something of the 
sort of

convert = {'0': '0000', '1': '0001', '2': '0010', ....}

and b) go thru all letters in the string and string their bin values 
together: 

This seems to work for me:

========================================

convert = {'0': '0000', '1': '0001', '2': '0010', '3': '0011',
           '4': '0100', '5': '0101', '6': '0110', '7': '0111',
           '8': '1000', '9': '1001', 'A': '1010', 'B': '1011',
           'C': '1100', 'D': '1101', 'E': '1110', 'F': '1111'}

hexstring = '38CF'   # our example
binstring = ''

for hexletter in hexstring:
    binstring = binstring + convert[hexletter]

print binstring

==========================================

Y, Scot