Given a list that contains only string elements the task here is to write a Python program to check if all of them are numeric or not. If all are numeric return True otherwise, return False.
Input : test_list = ["434", "823", "98", "74"] Output : True Explanation : All Strings are digits.
Input : test_list = ["434", "82e", "98", "74"] Output : False Explanation : e is not digit, hence verdict is False.
Method 1 : Using all(), isdigit() and generator expression
In this, we check for numbers from isdigit(). all() is used to check for all strings to be number, and iteration for each string is done using generator expression.
Example:
Python3
# initializing listtest_list = ["434", "823", "98", "74"]# printing original listprint("The original list is : " + str(test_list))# checking all elements to be numeric using isdigit()res = all(ele.isdigit() for ele in test_list)# printing resultprint("Are all strings digits ? : " + str(res)) |
The original list is : ['434', '823', '98', '74'] Are all strings digits ? : True
Time Complexity: O(n)
Auxiliary Space: O(n)
Method 2 : Using all(), isdigit() and map()
In this, we extend test logic to each string using map(), rather than generator expression. Rest all the functionalities are performed similarly to the above method.
Example:
Python3
# initializing listtest_list = ["434", "823", "98", "74"]# printing original listprint("The original list is : " + str(test_list))# checking all elements to be numeric using isdigit()# map() to extend to each elementres = all(map(str.isdigit, test_list))# printing resultprint("Are all strings digits ? : " + str(res)) |
The original list is : ['434', '823', '98', '74'] Are all strings digits ? : True
Time Complexity: O(n)
Auxiliary Space: O(n)
Method 3 : Using isnumeric() and len() methods
Python3
# initializing listtest_list = ["434", "82e", "98", "74"]# printing original listprint("The original list is : " + str(test_list))# checking all elements to be numeric using isdigit()c=0for i in test_list: if i.isnumeric(): c+=1res=Falseif(c==len(test_list)): res=True# printing resultprint("Are all strings digits ? : " + str(res)) |
The original list is : ['434', '82e', '98', '74'] Are all strings digits ? : False
Time Complexity: O(n)
Auxiliary Space: O(n)
Method 4 : Using replace() and len() methods
Python3
# Python Program to check whether all elements in a string list are numeric# initializing listtest_list = ["434", "82e", "98", "74"]# printing original listprint("The original list is : " + str(test_list))# checking all elements to be numeric using isdigit()c = 0numbers = "0123456789"for i in test_list: for j in numbers: i = i.replace(j, "") if(len(i) == 0): c += 1res = Falseif(c == len(test_list)): res = True# printing resultprint("Are all strings digits ? : " + str(res)) |
The original list is : ['434', '82e', '98', '74'] Are all strings digits ? : False
Time Complexity: O(n*n)
Auxiliary Space: O(n)
Method 5 : Using filter()+list()+lambda functions
Python3
# initializing listtest_list = ["434", "823", "98", "74"]# printing original listprint("The original list is : " + str(test_list))# checking all elements to be numeric using isdigit()res = list(filter(lambda x: x.isdigit(), test_list))if(len(res) == len(test_list)): res = Trueelse: res = False# printing resultprint("Are all strings digits ? : " + str(res)) |
The original list is : ['434', '823', '98', '74'] Are all strings digits ? : True
Time Complexity: O(n)
Auxiliary Space: O(n)
Method 6 : Using reduce()
Python3
from functools import reducefrom operator import and_test_list = ["434", "823", "98", "74"]print("The original list is : " + str(test_list))res = reduce(and_, (string.isdigit() for string in test_list))print("Are all strings digits ? : " + str(res))#This code is contributed by Jyothi pinjala. |
The original list is : ['434', '823', '98', '74'] Are all strings digits ? : True
Time Complexity: O(n)
Auxiliary Space: O(1)
Method 7:Using for loop
Python3
test_list = ["434", "823", "98", "74"]print("The original list is : " + str(test_list))for string in test_list: if not string.isdigit(): res = False breakelse: res = Trueprint("Are all strings digits ? : " + str(res))#This code is contributed by Vinay Pinjala. |
The original list is : ['434', '823', '98', '74'] Are all strings digits ? : True
Time complexity: O(n)
Auxiliary Space: O(1)
Method 8: Using loop +try and except method.
Python3
test_list = ["434", "823", "98", "74"]print("The original list is : " + str(test_list))for i in test_list: try: int(i) res=True except: res=Falseprint("Are all strings digits ? : " + str(res))#This code is contributed by tvsk. |
The original list is : ['434', '823', '98', '74'] Are all strings digits ? : True
Time complexity: O(n)
Auxiliary Space: O(1)
Method 9: Using re.match() method
Approach
- Initiate a for loop to traverse test_list, variable c=0
- Check whether each string is numeric or not using regular expression ^[0-9]+$ and method re.match() if yes increment c by 1
- If c equals to length of test_list then all strings have digits, set res to True or else False
- Display res
Python3
import re# initializing listtest_list = ["434", "823", "98", "74"]# printing original listprint("The original list is : " + str(test_list))# checking all elements to be# numeric using isdigit()c = 0for i in test_list: if re.match('^[0-9]+$', i): c += 1res = c == len(test_list)# printing resultprint("Are all strings digits ? : " + str(res)) |
The original list is : ['434', '823', '98', '74'] Are all strings digits ? : True
Time Complexity: O(N) N – length of test_list
Auxiliary Space: O(1) because we used single variable res to store result
