Union Operation of two Strings using Python

Python is a very commonly used language by programmers all over the world for different purposes such as machine learning, data science, web development and to perform many other operations with automation. It has many different features which help us to work on many different projects. One such feature of python is the union operation. The union operation means to combine two different strings into one common string after removing all the common elements in both the string. In this article we are going to learn about different methods which can be used for union operation of two strings.

Different Methods of Union Operation

Sets

Sets is a feature in python provided to store multiple items in one single data set. It has an inbuilt feature of removing all the common elements from the strings. Let’s take an example to understand it in a better way:

Example

def multiple_strings(first, second):  # The input of both the strings are given
    data1 = set(first)  # Both the strings are then converted into data sets
    data2 = set(second)
    union_data = data1.union(data2) # After conversion, the data sets are combined with the help of union operation
    final_string = ''.join(union_data) # The Combined data set is then converted back into strings
    return final_string

# Example 
first = "What"  # The two input strings are defined 
second = "Where"
final_result = multiple_strings(first, second) # The function multiple_strings is run
print(final_result) # The output after union Operation Will be shown

Output

The output of the above example will be as follows:

Wraeth  

Dictionary

In this method we will use the python dictionary for union operation. The dictionary will be used to store all the data as strings and then union operation will be performed over it. The example for union operation through this method is as follows:

Example

def multiple_strings(first, second): # The input of both the strings are given
    union_dict = {} # A new dictionary is created for the union operation
    for char in first:  # All the elements in both the strings are checked and then they are added in the new dictionary created
        union_dict[char] = True
    for char in second:
        union_dict[char] = True  # No duplicate characters will be added because dictionary keys will take input of different characters only
    union_string = ''.join(union_dict.keys())    # Once the union operation of the keys is performed, then we will convert the dictionary key back into string
    return union_string

# Example 
first = "What"  # The two input strings are defined 
second = "Where"
final_result = multiple_strings(first, second) # The function multiple_strings is run
print(final_result) # The output after union Operation Will be shown

Output

The output of the above example will look as follows:

Whater 

Checking List & Membership

This is a very simple method of performing the union operation. We will simply convert the string into list for the union operation. The example of this method is as follows:

Example

def multiple_strings(first, second): # The input of both the string is given
    combined_strings = list(first) # The first string is converted into a list
    for char in second:  #If the element in second string is not present in first string then they are combined into the first list and the union operation is performed
        if char not in combined_strings:
            combined_strings.append(char)
    final_string = ''.join(combined_strings) #The lists are then converted back into string
    return final_string

# Example 
first = "What"  # The two input strings are defined 
second = "Where"
final_result = multiple_strings(first, second) # The function multiple_strings is run
print(final_result) # The output after union Operation Will be shown

Output

The output of the above example will look as follows:

Whater  

Combined Use of Set and Pipe operators

This method is a complex method and should not be used in simple cases of combination. In this method the strings are converted into set and then instead of directly using the union, we will use pipe operators. Let’s take an example to understand it in a better way:

Example

def multiple_strings(first, second): # The input of both the string is given
    first_set = set(first) # Both the strings are converted into sets
    second_set = set(second)
    final_string = ''.join(first_set | second_set) # Using the pipe operator the respective sets are combined after removing the common elements
    return final_string

# Example 
first = "What"  # The two input strings are defined 
second = "Where"
final_result = multiple_strings(first, second) # The function multiple_strings is run
print(final_result) # The output after union Operation Will be shown

Output

The output of the above example will be as follows:

Wraeth 

Itertools Module

The itertools module is used for efficiently checking all the loops present in the data set. It has many different functions which can be used for many different purposes. We will use 2 such different functions to perform the union operation. Let’s take an example to understand it in better way:

Example

import itertools # Do not forget to import itertools or else error might occur
def unique_everseen(iterable, key=None):
    seen = set()
    seen_add = seen.add
    if key is None:  # The input of both the string is given
        for element in itertools.filterfalse(seen.__contains__, iterable):# Through the chain() function we will combine both the strings into cone common string
            seen_add(element)
            yield element
    else:
        for element in iterable:
            k = key(element)
            if k not in seen:
                seen_add(k)
                yield element

def multiple_strings(first, second):  # The input of both the string is given
    union_string = ''.join(unique_everseen(itertools.chain(string1, string2)))# With the help of unique.everseen() function we will remove all the common elements from the combined string
    return union_string

# Example 
first = "What"  # The two input strings are defined 
second = "Where"
final_result = multiple_strings(first, second) # The function multiple_strings is run
print(final_result) # The output after union Operation Will be shown

Output

The output of the above example will look as follows:

Wraeth 

Conclusion

It is very important to have knowledge about different methods that can be used to perform union operation. This article gives knowledge about different methods that can be used for the purpose of performing union operation. One can use any of the above mentioned method as per convenience and field of application.