CODEWITHSUNDEEP
pythonstringpython-2.7python-3.xwave
Ebrahim Ghasemi
Ebrahim Ghasemi

Reputation: 6126

How to remove '\x' from a hex string in Python?

I'm reading a wav audio file in Python using wave module. The readframe() function in this library returns frames as hex string. I want to remove \x of this string, but translate() function doesn't work as I want:

>>> input = wave.open(r"G:\Workspace\wav\1.wav",'r')
>>> input.readframes (1)
'\xff\x1f\x00\xe8'
>>> '\xff\x1f\x00\xe8'.translate(None,'\\x')
'\xff\x1f\x00\xe8'
>>> '\xff\x1f\x00\xe8'.translate(None,'\x')
ValueError: invalid \x escape
>>> '\xff\x1f\x00\xe8'.translate(None,r'\x')
'\xff\x1f\x00\xe8'
>>>

Any way I want divide the result values by 2 and then add \x again and generate a new wav file containing these new values. Does any one have any better idea?

What's wrong?

Upvotes: 4

Views: 19697

Answers (4)

Dmitry
Dmitry

Reputation: 442

Indeed, you don't have backslashes in your string. So, that's why you can't remove them.

If you try to play with each hex character from this string (using ord() and len() functions - you'll see their real values. Besides, the length of your string is just 4, not 16.

You can play with several solutions to achieve your result: 'hex' encode:

'\xff\x1f\x00\xe8'.encode('hex')
'ff1f00e8'

Or use repr() function:

repr('\xff\x1f\x00\xe8').translate(None,r'\\x')

Upvotes: 5

Ahasanul Haque
Ahasanul Haque

Reputation: 11144

As this is a hexadecimal representation, encode with hex

>>> '\xff\x1f\x00\xe8'.encode('hex')
'ff1f00e8'

Upvotes: 0

Omer Eldan
Omer Eldan

Reputation: 1767

Use the encode method:

>>> s = '\xff\x1f\x00\xe8'
>>> print s.encode("hex")
'ff1f00e8'

Upvotes: 3

Andrea Corbellini
Andrea Corbellini

Reputation: 17771

One way to do what you want is:

>>> s = '\xff\x1f\x00\xe8'
>>> ''.join('%02x' % ord(c) for c in s)
'ff1f00e8'

The reason why translate is not working is that what you are seeing is not the string itself, but its representation. In other words, \x is not contained in the string:

>>> '\\x' in '\xff\x1f\x00\xe8'
False

\xff, \x1f, \x00 and \xe8 are the hexadecimal representation of for characters (in fact, len(s) == 4, not 24).

Upvotes: 5

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