Python: Best Way to remove duplicate character from string

问题

How can I remove duplicate characters from a string using Python? For example, let's say I have a string:

foo = "SSYYNNOOPPSSIISS"

How can I make the string:

foo = SYNOPSIS

I'm new to python and What I have tired and it's working. I knew there is smart and best way to do this.. and only experience can show this..

def RemoveDupliChar(Word):
        NewWord = " "
        index = 0
        for char in Word:
                if char != NewWord[index]:
                        NewWord += char
                        index += 1
        print(NewWord.strip())

NOTE: Order is important and this question is not similar to this one.

回答1:

Using itertools.groupby:

>>> foo = "SSYYNNOOPPSSIISS"
>>> import itertools
>>> ''.join(ch for ch, _ in itertools.groupby(foo))
'SYNOPSIS'

回答2:

This is a solution without importing itertools:

foo = "SSYYNNOOPPSSIISS"
''.join([foo[i] for i in range(len(foo)-1) if foo[i+1]!= foo[i]]+[foo[-1]])

Out[1]: 'SYNOPSIS'

But it is slower than the others method!

回答3:

How about this:

oldstring = 'SSSYYYNNNOOOOOPPPSSSIIISSS'
newstring = oldstring[0]
for char in oldstring[1:]:
    if char != newstring[-1]:
        newstring += char

回答4:

def remove_duplicates(astring):
  if isinstance(astring,str) :
    #the first approach will be to use set so we will convert string to set and then convert back set to string and compare the lenght of the 2
    newstring = astring[0]
    for char in astring[1:]:
        if char not in newstring:
            newstring += char    
    return newstring,len(astring)-len(newstring)
  else:
raise TypeError("only deal with alpha  strings")

I've discover that solution with itertools and with list comprehesion even the solution when we compare the char to the last element of the list doesn't works

回答5:

def removeDuplicate(s):  
    if (len(s)) < 2:
        return s

    result = []
    for i in s:
        if i not in result:
            result.append(i)

    return ''.join(result)

回答6:

How about

foo = "SSYYNNOOPPSSIISS"


def rm_dup(input_str):
    newstring = foo[0]
    for i in xrange(len(input_str)):
        if newstring[(len(newstring) - 1 )] != input_str[i]:
            newstring += input_str[i]
        else:
            pass
    return newstring

print rm_dup(foo)

回答7:

You can try this:

string1 = "example1122334455"
string2 = "hello there"

def duplicate(string):
    temp = ''

    for i in string:
        if i not in temp: 
            temp += i

    return temp;

print(duplicate(string1))
print(duplicate(string2))

来源：https://stackoverflow.com/questions/18799036/python-best-way-to-remove-duplicate-character-from-string

标签

python

string

text-processing