Remove all duplicates from a given string in Python
We are given a string and we need to remove all duplicates from it? What will be the output if the order of character matters?
Examples:
Input : geeksforgeeks Output : efgkos
Method 1:
from collections import OrderedDict # Function to remove all duplicates from string # and order does not matter def removeDupWithoutOrder(str): # set() --> A Set is an unordered collection # data type that is iterable, mutable, # and has no duplicate elements. # "".join() --> It joins two adjacent elements in # iterable with any symbol defined in # "" ( double quotes ) and returns a # single string return "".join(set(str)) # Function to remove all duplicates from string # and keep the order of characters same def removeDupWithOrder(str): return "".join(OrderedDict.fromkeys(str)) # Driver program if __name__ == "__main__": str = "geeksforgeeks" print ("Without Order = ",removeDupWithoutOrder(str)) print ("With Order = ",removeDupWithOrder(str)) |
Output:
Without Order = egfkosr With Order = geksfor
Method 2:
def removeDuplicate(str): s=set(str) s="".join(s) print("Without Order:",s) t="" for i in str: if(i in t): pass else: t=t+i print("With Order:",t) str="geeksforgeeks"removeDuplicate(str) |
Output:
Without Order: rofgeks With Order: geksfor
What do OrderedDict and fromkeys() do ?
An OrderedDict is a dictionary that remembers the order of the keys that were inserted first. If a new entry overwrites an existing entry, the original insertion position is left unchanged.
For example see below code snippet :
from collections import OrderedDict ordinary_dictionary = {}ordinary_dictionary['a'] = 1ordinary_dictionary['b'] = 2ordinary_dictionary['c'] = 3ordinary_dictionary['d'] = 4ordinary_dictionary['e'] = 5 # Output = {'a': 1, 'c': 3, 'b': 2, 'e': 5, 'd': 4}print (ordinary_dictionary) ordered_dictionary = OrderedDict()ordered_dictionary['a'] = 1ordered_dictionary['b'] = 2ordered_dictionary['c'] = 3ordered_dictionary['d'] = 4ordered_dictionary['e'] = 5 # Output = {'a':1,'b':2,'c':3,'d':4,'e':5}print (ordered_dictionary) |
fromkeys() creates a new dictionary with keys from seq and values set to value and returns list of keys, fromkeys(seq[, value]) is the syntax for fromkeys() method.
Parameters :
- seq : This is the list of values which would be used for dictionary keys preparation.
- value : This is optional, if provided then value would be set to this value.
For example see below code snippet :
from collections import OrderedDictseq = ('name', 'age', 'gender')dict = OrderedDict.fromkeys(seq) # Output = {'age': None, 'name': None, 'gender': None}print (str(dict)) dict = OrderedDict.fromkeys(seq, 10) # Output = {'age': 10, 'name': 10, 'gender': 10}print (str(dict)) |
Last Updated on November 8, 2021 by admin