Python | Slice String from Tuple ranges

Sometimes, while working with data, we can have a problem in which we need to perform the removal from strings depending on specified substring ranges. Let’s discuss certain ways in which this task can be performed.

Method #1: Using loop + list slicing: This is the brute force task to perform this task. In this, we remake the String by carefully omitting the slice ranges using list slicing. The iteration of tuples is done by the loop. 

Python3

# Python3 code to demonstrate working of
# Slice String from Tuple ranges
# using loop + list slicing

# initialize list and string
test_list = [(2, 4), (5, 9), (13, 17), (24, 27)]

test_str = "geeksforgeeks is best for geeks and programming"

# printing original list and string
print("The original list : " + str(test_list))
print("The original string : " + str(test_str))

# Slice String from Tuple ranges
# using loop + list slicing
for front, rear in reversed(test_list):
    test_str = test_str[: front] + test_str[rear + 1:]

# printing result
print("The String after slicing is : " + str(test_str))

Output : 

The original list : [(2, 4), (5, 9), (13, 17), (24, 27)]
The original string : geeksforgeeks is best for geeks and programming
The String after slicing is : geeksest foeks and programming

Time Complexity: O(n)
Auxiliary Space: O(n)

Method #2: Using join() + any() + generator expression: The combination of these functionalities can also be used to perform this task. In this, we perform the task of slicing using generator expression, and exclusion is handled by any(). The creation of a modified string is done by join(). 

Python3

# Python3 code to demonstrate working of
# Slice String from Tuple ranges
# using join() + any() + generator expression

# initialize list and string
test_list = [(2, 4), (5, 9), (13, 17), (24, 27)]

test_str = "geeksforgeeks is best for geeks and programming"

# printing original list and string
print("The original list : " + str(test_list))
print("The original string : " + str(test_str))

# Slice String from Tuple ranges
# using join() + any() + generator expression
res = "".join(test_str[idx] for idx in range(len(test_str))\
 if not any(front <= idx <= rear for front, rear in test_list))


# printing result
print("The String after slicing is : " + str(res))

Output : 

The original list : [(2, 4), (5, 9), (13, 17), (24, 27)]
The original string : geeksforgeeks is best for geeks and programming
The String after slicing is : geeksest foeks and programming

Time Complexity: O(n)
Auxiliary Space: O(n)