Generate output without losing leading zeroes

Question

I am using sage maths (which uses Python(more or less)) to do some work involving cryptography. This involves using binary keys which you xor to generate a cipher or message. Often, the input data is nn hex and so I have to convert to binary to see what is going on. Here is an example of the kind of thing I am doing once I have my binary.

my_cip=0b01101.....
my_mes=0b0110....
ot_mes=0b011...
my_key=0b0000....
key_fn=0b00....
altcip=0b011011..
print my_key.__xor__(ot_mes).binary()

The problem is that when I use utility functions to convert ascii to binary and hex to binary, the result has any leading zeroes thrown away.

I do not know how many have been thrown away so I have been predicting how many bits should be in the result and sticking the appropriate number of zeroes on the front of the result.

Here is my question! Is there a way of forcing the leading zeroes to be included in the result of calling (for example) ?

`print Integer(0x6c73.....).binary() ?`

If you post that as an answer I will credit it with a tick. Thank you. — nerak99, Nov 25 '12 at 18:37

score 2 · Answer 1 · answered Nov 25 '12 at 17:35

2

Use format()

See documentation Python format documentation

answered Nov 25 '12 at 17:35

crow16384

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Thank you for your contribution. zmbq drilled down to the specific answer that I was after which is a subset of format. – nerak99 Nov 25 '12 at 18:39

score 1 · Accepted Answer · edited May 23 '17 at 12:04

1

You can find a similar issue here. It shows you how to pad zeroes very nicely.

edited May 23 '17 at 12:04

Community

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answered Nov 25 '12 at 18:51

zmbq

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Generate output without losing leading zeroes

2 Answers2