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multi-replace (Python recipe) by John Nielsen
ActiveState Code (http://code.activestate.com/recipes/259100/)

This class replaces characters until there are no offending ones left.

You could you regex or translate. This is a method using dictionaries and replace method from strings.

Python, 33 lines
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import string

class multi_replace:
    def __init__(self,keep=[],debug=''):
        self.keep={};self.debug=0
        if debug: self.debug=1
        if keep:
            for i in keep: self.keep[i]=1
        else:
            #keep all keyboard characters plus whitespace
            for i in string.printable: self.keep[i]=1
        
            #remove space characters except for ' '
            for i in string.whitespace:
                if i==' ': continue #whitespace is valid
                if i in self.keep: del self.keep[i]

    def replace(self,line,new_char):
        bad=0;changed=0
        #keep on replacing until there are no bad characters left
        while 1:
            clean=1
            for c in line:
                if c not in self.keep:
                    clean=0
                    line=line.replace(c,new_char)
                    changed=1
                    #cannot continue replacing since line has changed w/for loop
                    break
            #break the while loop if nothing bad was found
            if clean: break
            if self.debug and changed: print line
        return line

This is good for filtering logfiles. Here is an example.

by default only accept keyboard chars and ' '

you can also provide a list of chars

m=multi_replace() f=open('e.log') for line in f: line=line.strip() #replace all unacceptable chars with # line=m.replace(line,'#')

If you want to print to the screen every time it changes a line, set debug=1 m=multi_replace(debug=1)

Tags: shortcuts