115
votes

The hex() function in python, puts the leading characters 0x in front of the number. Is there anyway to tell it NOT to put them? So 0xfa230 will be fa230.

The code is

import fileinput
f = open('hexa', 'w')
for line in fileinput.input(['pattern0.txt']):
   f.write(hex(int(line)))
   f.write('\n')
7
You can slice the 0x. - Ashwini Chaudhary
@AshwiniChaudhary I think he is essentially asking how to slice the 0x - Mine

7 Answers

213
votes
>>> format(3735928559, 'x')
'deadbeef'
65
votes

Use this code:

'{:x}'.format(int(line))

it allows you to specify a number of digits too:

'{:06x}'.format(123)
# '00007b'

For Python 2.6 use

'{0:x}'.format(int(line))

or

'{0:06x}'.format(int(line))
21
votes

You can simply write

hex(x)[2:]

to get the first two characters removed.

16
votes

Python 3.6+:

>>> i = 240
>>> f'{i:02x}'
'f0'
7
votes

Old style string formatting:

In [3]: "%02x" % 127
Out[3]: '7f'

New style

In [7]: '{:x}'.format(127)
Out[7]: '7f'

Using capital letters as format characters yields uppercase hexadecimal

In [8]: '{:X}'.format(127)
Out[8]: '7F'

Docs are here.

2
votes

'x' - Outputs the number in base 16, using lower-case letters for the digits above 9.

>>> format(3735928559, 'x')
'deadbeef'

'X' - Outputs the number in base 16, using upper-case letters for the digits above 9.

>>> format(3735928559, 'X')
'DEADBEEF'

You can find more informations about that in Python's documentation: https://docs.python.org/3.8/library/string.html#formatspec https://docs.python.org/3.8/library/functions.html#format

0
votes

While all of the previous answers will work, a lot of them have caveats like not being able to handle both positive and negative numbers or only work in Python 2 or 3. The version below works in both Python 2 and 3 and for positive and negative numbers:

Since Python returns a string hexadecimal value from hex() we can use string.replace to remove the 0x characters regardless of their position in the string (which is important since this differs for positive and negative numbers).

hexValue = hexValue.replace('0x','')