Question

Okay, so I made this little function that allows me to make a string into multiplier of 32 characters, but when I use String .replace I get some really, really weird bug. Since its making me pull my hair, can you guys take a look and see what I’m missing.

Variables:
        self.blockSize = 32
        self.interrupt = '$^EnD#Block^$'
        self.filler = '#'

Functions:
    def pad(self, data):
        joint1 = ''.join([data, self.interrupt])
        joint2 = self.filler * ((self.blockSize - len(joint1)) % self.blockSize) 
        return ''.join([joint1, joint2])

    def unpad(self, data):
        data = str(data).rstrip(self.interrupt)
        return data.replace(self.filler, '')

Call:
p = e.pad('this is not a very good idea  yo')
print(p)
print(e.unpad(p))


Output:
    Jans-MacBook-Pro:test2 jan$ ../../bin/python3 data.py 
    this is not a very good idea  yo123$^EnD#Block^$################
    this is not a very good idea  yo123
    Jans-MacBook-Pro:test2 jan$ ../../bin/python3 data.py 
    this is not a very good idea  yo$^EnD#Block^$###################
    this is not a very good idea  y
    Jans-MacBook-Pro:test2 jan$ 

It makes o in yo disappear. Ahhhh! But nothing disappears if I add some random numbers after.

SOLUTION – EDIT: My bad. I have misplaced self.filler and self.interrupt. I am so embarrassed now. The code should have been:

def unpad(self, data):
    data = str(data).rstrip(self.filler)
    return data.replace(self.interrupt, '')

Answer 1

Read the documentation for rstrip:

The chars argument is a string specifying the set of characters to be removed.

rstrip removes all trailing characters present in the passed set of characters. It doesn’t remove a trailing substring consisting of those characters in that order. 'abczyx'.rstrip('xyz') gives 'abc', and 'abczyx'.rstrip('zyx') also gives 'abc'.