Given the Strings list, write a Python program to increment strings that are numeric by K.
Examples:
Input : test_list = [“gfg”, “234”, “is”, “98”, “123”, “best”, “4”], K = 6
Output : [‘gfg’, ‘240’, ‘is’, ‘104’, ‘129’, ‘best’, ’10’]
Explanation : 234, 98 and 4 are incremented by 6 in result.Input : test_list = [“gfg”, “234”, “is”, “98”, “123”, “best”, “4”], K = 4
Output : [‘gfg’, ‘238’, ‘is’, ‘102’, ‘129’, ‘best’, ‘8’]
Explanation : 234, 98 and 4 are incremented by 4 in result.
Method #1 : Using str() + int() + loop + isdigit()
In this, we perform task of interconversion of elements using str() + int(), and check for number using isdigit(), iteration is done using loop.
Python3
# Python3 code to demonstrate working of# Increment Numeric Strings by K# Using str() + int() + loop + isdigit()# initializing Matrixtest_list = ["gfg", "234", "is", "98", "123", "best", "4"]# printing original listprint("The original list is : " + str(test_list))# initializing KK = 6res = []for ele in test_list: # incrementing on testing for digit. if ele.isdigit(): res.append(str(int(ele) + K)) else: res.append(ele)# printing resultprint("Incremented Numeric Strings : " + str(res)) |
Output:
The original list is : [‘gfg’, ‘234’, ‘is’, ’98’, ‘123’, ‘best’, ‘4’] Incremented Numeric Strings : [‘gfg’, ‘240’, ‘is’, ‘104’, ‘129’, ‘best’, ’10’]
Time Complexity: O(n)
Auxiliary Space: O(n)
Method #2 : Using list comprehension + isdigit()
This is one of the ways in which this task can be performed. Similar to above, just one line alternative to compact the solution using list comprehension.
Python3
# Python3 code to demonstrate working of# Increment Numeric Strings by K# Using list comprehension + isdigit()# initializing Matrixtest_list = ["gfg", "234", "is", "98", "123", "best", "4"]# printing original listprint("The original list is : " + str(test_list))# initializing KK = 6# increment Numeric digits.res = [str(int(ele) + K) if ele.isdigit() else ele for ele in test_list]# printing resultprint("Incremented Numeric Strings : " + str(res)) |
Output:
The original list is : [‘gfg’, ‘234’, ‘is’, ’98’, ‘123’, ‘best’, ‘4’] Incremented Numeric Strings : [‘gfg’, ‘240’, ‘is’, ‘104’, ‘129’, ‘best’, ’10’]
Time Complexity: O(n*n), where n is the number of elements in the list “test_list”.
Auxiliary Space: O(n), where n is the number of elements in the list “test_list”.
Method #3 : Without using any built-in methods
Python3
# Python3 code to demonstrate working of# Increment Numeric Strings by K# checking whether string is numeric or notdef numeric(num): digits="0123456789" c=0 for i in num: if i in digits: c+=1 if(c==len(num)): return True return False# initializing listtest_list = ["gfg", "234", "is", "98", "123", "best", "4"]# printing original listprint("The original list is : " + str(test_list))# initializing KK = 6new_list=[]# increment numeric strings.for i in test_list: if(numeric(i)): new_list.append(str(int(i)+K)) else: new_list.append(i)# printing resultprint("Incremented Numeric Strings : " + str(new_list)) |
The original list is : ['gfg', '234', 'is', '98', '123', 'best', '4'] Incremented Numeric Strings : ['gfg', '240', 'is', '104', '129', 'best', '10']
The time and space complexity for all the methods are the same:
Time Complexity: O(n)
Space Complexity: O(n)
Method #4 : Using isnumeric() method
Python3
# Python3 code to demonstrate working of# Increment Numeric Strings by K# initializing Matrixtest_list = ["gfg", "234", "is", "98", "123", "best", "4"]# printing original listprint("The original list is : " + str(test_list))# initializing KK = 6res = []for i in test_list: if i.isnumeric(): res.append(str(int(i)+K)) else: res.append(i)# printing resultprint("Incremented Numeric Strings : " + str(res)) |
The original list is : ['gfg', '234', 'is', '98', '123', 'best', '4'] Incremented Numeric Strings : ['gfg', '240', 'is', '104', '129', 'best', '10']
Method#5:Using map and lambda
Python3
def increment_numeric_strings(lst, K): return list(map(lambda x: str(int(x) + K) if x.isdigit() else x, lst))test_list = ["gfg", "234", "is", "98", "123", "best", "4"]print("The original list is:", test_list)print("Incremented Numeric Strings:", increment_numeric_strings(test_list, 6))#This code is contributed by Vinay pinjala. |
The original list is: ['gfg', '234', 'is', '98', '123', 'best', '4'] Incremented Numeric Strings: ['gfg', '240', 'is', '104', '129', 'best', '10']
Time Complexity: O(n)
Auxiliary Space: O(1)
Method#6: Here’s a solution using try/except:
In this solution, we use a try/except block to check if the element can be converted to an integer. If it can, we increment it by K and add the result to the result list. If the conversion fails, we know that the element is not a number and we add it to the result list as is.
Python3
def increment_numeric_strings(test_list, K): result = [] for ele in test_list: try: number = int(ele) result.append(str(number + K)) except ValueError: result.append(ele) return resulttest_list = ["gfg", "234", "is", "98", "123", "best", "4"]K = 6print(increment_numeric_strings(test_list, K)) |
['gfg', '240', 'is', '104', '129', 'best', '10']
The time complexity of this solution is O(n), where n is the number of elements in test_list. The space complexity is O(n), as we are creating a new list result of the same size as test_list.
