Anagrams in Python using lists

finding anagrams in a list python
anagram program in python without using inbuilt methods
find anagrams in a list of words
remove anagrams from list
anagram finder python
anagrams algorithm
sort anagrams
hashing anagrams

Imagine we have following list of strings:

Input: ["eat", "tea", "tan", "ate", "nat", "bat"]

The output of our program should group each set of anagram and return them all together as a list as following:

Output:
[
  ["ate","eat","tea"],
  ["nat","tan"],
  ["bat"]
]

My current solution finds the first set of anagrams but fails to detect the other two and instead, duplicates the first groups into the list:

class Solution(object):
    def groupAnagrams(self, strs):
        allResults=[]
        results=[]
        temp=''
        for s in strs:  
          temp=s[1:]+s[:1]
          for i in range(0,len(strs)):
              if temp==strs[i]:
                results.append(strs[i])
          allResults.append(results)      
        return allResults 

and the output is:

[["ate","eat","tea"],["ate","eat","tea"],["ate","eat","tea"],["ate","eat","tea"],["ate","eat","tea"],["ate","eat","tea"]]

How to fix this issue?

EDIT: I have fixed the duplication in appending by appending the results into allResults outside of second loop:

class Solution(object):
def groupAnagrams(self, strs):
    allResults=[]
    results=[]
    temp=''
    for s in strs:  
      temp=s[1:]+s[:1]
      for i in range(0,len(strs)):
          if temp==strs[i]:
            results.append(strs[i])
    allResults.append(results) 
    print(results)
    return allResults  

Yet, it does not detect the other two sets of anagrams.

you can do it using defaultdict of python in-built collections library and sorted :

In [1]: l = ["eat", "tea", "tan", "ate", "nat", "bat"]

In [2]: from collections import defaultdict

In [3]: d = defaultdict(list)

In [4]: for x in l:
   ...:     d[str(sorted(x))].append(x)

In [5]: d.values()
Out[5]: dict_values([['eat', 'tea', 'ate'], ['tan', 'nat'], ['bat']])

to fix your the solution you need add the variable to check is allready added, for exanmple(and the while walk through the strs i use enumerate for little performance in the search of the anagrams):

class Solution(object):
    def groupAnagrams(self, strs):
        allResults = []
        added = set([])
        temp=''
        for i, s in enumerate(strs):
            results = []
            unique_s = "".join(sorted(s))
            if unique_s in added:
                continue
            else:
                added.add(unique_s)
            for x in strs[i:]:
              if unique_s=="".join(sorted(x)):
                results.append(strs[i])
            allResults.append(results)
        print(added)
        return allResults

Python, In this, we first get the anagrams grouped using defaultdict and use sorted function to get each anagram root value to group anagrams. filter_none. edit close. Given an array of words, print all anagrams together ? This problem has existing solution please refer Anagrams and Given a sequence of words, print all anagrams together links. We will solve this problem in python using List and Dictionary data structures. Approach is very simple : Sort each string in ascending order and consider this sorted

Use itertools.groupby

>>> lst =  ["eat", "tea", "tan", "ate", "nat", "bat"]
>>> 
>>> from itertools import groupby
>>> f = lambda w: sorted(w)
>>> [list(v) for k,v in groupby(sorted(lst, key=f), f)]
[['bat'], ['eat', 'tea', 'ate'], ['tan', 'nat']]

Using Python, find anagrams for a list of words, In order to do this for 2 strings you can do this: def isAnagram(str1, str2): str1_list = list(str1) str1_list.sort() str2_list = list(str2) str2_list.sort() return (str1_list  In this tutorial, we are going to write a program which finds and prints anagrams using list and dictionary. We have different approaches to every problem. Try to write code without following the tutorial. If you are not able to generate any ideas to write logic, follow the below steps. Algorithm 1. Initialize a list of strings. 2.

Using only lists, as requested in the title of the question:

The second line s_words takes all the letters of each word in words, sorts them, and recreates a string composed of the sorted letters of the word; it creates a list of all the these sorted letters strings, in the same order as the original sequence of words --> this will be used to compare the possible anagrams (the letters of anagrams produce the same string when sorted)

The 3rd line indices hold True or False values, to indicate if the corresponding word has been extracted already, and avoid duplicates.

The following code is a double loop that for each s_word, determines which other s_word is identical, and uses its index to retrieve the corresponding word in the original list of words; it also updates the truth value of the indices.

words = ["eat", "tea", "tan", "ate", "nat", "bat"]
s_words = [''.join(sorted(list(word))) for word in words]
indices = [False for _ in range(len(words))]
anagrams = []
for idx, s_word in enumerate(s_words):
    if indices[idx]:
        continue
    ana = [words[idx]]
    for jdx, word in enumerate(words):
        if idx != jdx and not indices[jdx] and s_word == s_words[jdx]:
            ana.append(words[jdx])
            indices[jdx] = True
    anagrams.append(ana)

print(anagrams)
output:
[['eat', 'tea', 'ate'], ['tan', 'nat'], ['bat']]

Print anagrams together in Python using List and Dictionary, In this tutorial, we are going to write a program which finds and prints anagrams using list and dictionary. We have different approaches to every  One solution is to sort the word you're searching anagrams for (for example using sorted), sort the alternative and compare those. So if you would be searching for anagrams of 'rac' in the list ['car', 'girl', 'tofu', 'rca'], your code could look like this: Sort each element then look for duplicates.

The way you implemented your function, you are only looking at rotations of the strings (that is you shift a letter from the beginning to the end, e.g. a-t-e -> t-e-a -> e-a-t). What your algorithm cannot detect is single permutations were you only switch two letters (n-a-t -> t-a-n). In mathematical language you only consider the even permutations of the three letter strings and not the odd permutations.

A modification of your code could for example be:

def get_list_of_permutations(input_string):
  list_out = []
  if len(input_string) > 1:
    first_char = input_string[0]
    remaining_string = input_string[1:]
    remaining_string_permutations = get_list_of_permutations(remaining_string)
    for i in range(len(remaining_string)+1):
      for permutation in remaining_string_permutations:
        list_out.append(permutation[0:i]+first_char+permutation[i:])
  else:
    return [input_string]
  return list_out

def groupAnagrams(strs):
  allResults=[]
  for s in strs:  
    results = []
    list_of_permutations = get_list_of_permutations(s)
    for i in range(0,len(strs)):
      if strs[i] in list_of_permutations:
        results.append(strs[i])
    if results not in allResults:
      allResults.append(results)     
  return allResults 

The output is

Out[218]: [['eat', 'tea', 'ate'], ['tan', 'nat'], ['bat']]

Edit: modified the code to work with all lengths of strings.

Detecting Anagrams Using Python - Analytics Vidhya, Task: Write a program that takes in a word list and outputs a list of all the words that are anagrams of another word in the list. Before starting, it is  In the GIF above, the words supersonic and percussion have the exact same letters used. The words are anagrams of each other. For example, Car and Arc are anagrams of each other as well as Leaf and Flea. In this blog, we will build a simple code using python that can identify anagrams from the given input.

https://docs.python.org/3/library/itertools.html#itertools.permutations

from itertools import permutations

word_list = ["eat", "tea", "tan", "ate", "nat", "bat"]
anagram_group_list = []

for word in word_list:

    if word == None:
        pass
    else:
        anagram_group_list.append([])

        for anagram in permutations(word):
            anagram = ''.join(anagram)

            try:
                idx = word_list.index(anagram)
                word_list[idx] = None 

                anagram_group_list[-1].append(anagram)

            except ValueError:
                pass # this anagram is not present in word_list

print(anagram_group_list)
# [['eat', 'ate', 'tea'], ['tan', 'nat'], ['bat']]

after refactoring code and stopping it from producing redundant result your code still doesn't give expected result as logic for producing anagram is not completely correct

def groupAnagrams(word_list):
    allResults=[]
    results=[]

    for idx,s in enumerate(word_list):
        if s == None:
            pass
        else:
            results = [s] # word s is added to anagram list

            # you were generating only 1 anagram like for tan --> ant but in word_list only nat was present
            for i in range(1,len(s),1):
                temp = s[i:]+s[:i] #anagram 
                    # for s = 'tan' it generates only 'ant and 'nta'
                    # when it should generate all six tna ant nta _nat_ atn tan

                if temp in word_list:
                  results.append(temp)
                  word_list[word_list.index(temp)] = None

            allResults.append(results) 

    return allResults

print(groupAnagrams(["eat", "tea", "tan", "ate", "nat", "bat"]))
# [['eat', 'ate', 'tea'], ['tan'], ['nat'], ['bat']]

Python Tutorials, is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once. 2. The characters of both the strings are sorted into separate lists. 3. They are then checked whether they are equal or not using an if statement. 4. If they are equal, they are anagrams as the characters are simply jumbled in anagrams. 5. If they aren’t equal, the strings aren’t anagrams. 6. The final result is printed.

Interesting questions: Anagram Numbers – data science tools and , How do you check if two strings are anagrams of each other in python? Anagram checking in Python using collections.Counter() Write a function to check whether two given strings are anagram of each other or not. An anagram of a string is another string that contains same characters, only the order of characters can be different.

Find anagrams of a word in a list, both be formed by rearranging the same combination of digits. Python Anagram Solver. Raghav Gurung. Follow. Aug 8, 2019 · 5 min read. A simple and efficient way to get all anagrams from a scrambled letter using Python.

How to Check for Anagrams Using Python, Python has an official style-guide, PEP8, which is well worth a read. It recommends not using parenthesis in if (and while ) statements, so this  Python Challenges - 1: Exercise-26 with Solution. Write a Python program to check if a given string is an anagram of another given string. According to Wikipedia an anagram is direct word switch or word play, the result of rearranging the letters of a word or phrase to produce a new word or phrase, using all the original letters exactly once; for example, the word anagram can be rearranged

Comments
  • Hints: What is the value of results when you enter the second iteration of the loop? What is the value of allResults on each iteration? (Print them and look.)
  • @molbdnilo Do you mean right before if temp...?
  • Print them after appending to allResults.
  • @molbdnilo Understood, I know the trouble is appending at wrong loop, but as Python has no {} for blocks and uses indentation instead, it is confusing me. Am I getting it correctly?
  • @molbdnilo The duplication in appending has been fixed, yet, it does not detect the other two sets of anagrams. How to solve this?
  • very nice, but can you modify my own code? I would like to know where in my code is wrong in order to improve my understanding from python as a new comer.
  • Using set to find the anagrams won't work if you have duplicate letters in some words. Your code would consider 'hat' and 'that' to be anagrams.
  • @ReblochonMasque the main trouble was using set i fixed, thank you
  • @Ionesome i extended the answer for your solution
  • It seems it has a bit of problem. In my opinion, your code changes input strs and returns them as output. I guess they shouldnt get changed.
  • Could you please explain your code? Specially the second line.