Python – Replace Substrings from String List

Sometimes while working with data, we can have a problem in which we need to perform replace substrings with the mapped string to form a short form of some terms. This kind of problem can have applications in many domains involving data. Let’s discuss certain ways in which this task can be performed.

Method #1 : Using loop + replace() + enumerate()
The combination of the above functions can be used to perform this task. In this, we perform the task of iteration using loop and enumerate() and replacement with a shorter form is done using replace().

Python3

# Python3 code to demonstrate
# Replace Substrings from String List
# using loop + replace() + enumerate()

# Initializing list1
test_list1 = ['GeeksforGeeks', 'is', 'Best', 'For', 'Geeks', 'And', 'Computer Science']
test_list2 = [['Geeks', 'Gks'], ['And', '&'], ['Computer', 'Comp']]

# printing original lists
print("The original list 1 is : " + str(test_list1))
print("The original list 2 is : " + str(test_list2))

# Replace Substrings from String List
# using loop + replace() + enumerate()
sub = dict(test_list2)
for key, val in sub.items():
    for idx, ele in enumerate(test_list1):
        if key in ele:
            test_list1[idx] = ele.replace(key, val)

# printing result
print ("The list after replacement : " + str(test_list1))

Output : 

The original list 1 is : ['GeeksforGeeks', 'is', 'Best', 'For', 'Geeks', 'And', 'Computer Science']
The original list 2 is : [['Geeks', 'Gks'], ['And', '&'], ['Computer', 'Comp']]
The list after replacement : ['GksforGks', 'is', 'Best', 'For', 'Gks', '&', 'Comp Science']

Method #2 : Using replace() + list comprehension
This is another way in which this task can be performed. In this, we perform the task of replacing using the replace(), and the rest of the task is performed using list comprehension. It removes lists that don’t have replacements.

Python3

# Python3 code to demonstrate
# Replace Substrings from String List
# using replace() + list comprehension

# Initializing list1
test_list1 = ['GeeksforGeeks', 'is', 'Best', 'For', 'Geeks', 'And', 'Computer Science']
test_list2 = [['Geeks', 'Gks'], ['And', '&'], ['Computer', 'Comp']]

# printing original lists
print("The original list 1 is : " + str(test_list1))
print("The original list 2 is : " + str(test_list2))

# Replace Substrings from String List
# using replace() + list comprehension
res = [sub.replace(sub2[0], sub2[1]) for sub in test_list1
      for sub2 in test_list2 if sub2[0] in sub]

# printing result
print ("The list after replacement : " + str(res))

Output : 

The original list 1 is : ['GeeksforGeeks', 'is', 'Best', 'For', 'Geeks', 'And', 'Computer Science']
The original list 2 is : [['Geeks', 'Gks'], ['And', '&'], ['Computer', 'Comp']]
The list after replacement : ['GksforGks', 'Gks', '&', 'Comp Science']