Multiple ways to remove duplicates from a list order without Python with examples

This tutorial explains about removing duplicates from the list and with or without order guaranteed

#How to remove duplicates from the list

Set is a data structure used to remove duplicate elements and order is guaranteed.

• Use Set constructor

Step 1: Convert List to Set using the constructor. Step 2: Sets remove duplicates and return unordered items.

numbers=[1,3,5,7,9,1];
result = list(set(numbers))
print(result)

#How to remove duplicate list by preserving order

Multiple ways to return unique elements from a list by preserving order

• Python Dictionary in 3.7 and below versions

Dictionary(dict) elements are keys ordered in insertion order from Python 3.7 version,

Convert the list into a dictionary using dict.fromKeys(list) function, It removes duplicates and again converts them into a list using the list() constructor.

numbers=[1,3,5,7,9,1];
print(list(dict.fromkeys(numbers))); # [1,3,5,7,9]

Python 3.6 version before, you can use OrderDict class from Collections package

from collections import OrderedDict
numbers=[1,3,5,7,9,1];

print(list(OrderedDict.fromkeys(numbers))) # [1,3,5,7,9]

• use Pandas package

  • The panda’s package provides Series function that accepts lists,
  • drop_duplicates() removes the duplicate elements
  • Convert to list using toList() function

import pandas as pd
numbers=[1,3,5,7,9,1];
print(pd.Series(my_list).drop_duplicates().tolist())

• use for loop and if conditional statements

• Iterate a list using for loop

• check an element using uniqueList, this list was created empty initially

• if elements exist, append them to a unique list

numbers=[1,3,5,7,9,1];
uniqueList = []
for name in numbers:
    if name not in uniqueList:
        uniqueList.append(name)

print(uniqueList)