Given a string, the task is to write a Python program to move all the numbers in it to its end.
Examples:
Input : test_str = ‘geek2eeks4g1eek5sbest6forall9’
Output : geekeeksLazyroarbestforall241569
Explanation : All numbers are moved to end.Input : test_str = ‘geekeeksg1eek5sbest6forall9’
Output : geekeeksLazyroarbestforall1569
Explanation : All numbers are moved to end.
Method 1 : Using isdigit() and loop
In this, we check elements and digits using isdigit(), keeping track of all the numbers and append at end of string post iteration.
Python3
# initializing stringtest_str = 'geek2eeks4g1eek5sbest6forall9'# printing original stringprint("The original string is : " + str(test_str))# getting all numbers and removing digitsres = ''dig = ''for ele in test_str: if ele.isdigit(): dig += ele else: res += ele# adding digits at endres += dig# printing resultprint("Strings after digits at end : " + str(res)) |
The original string is : geek2eeks4g1eek5sbest6forall9 Strings after digits at end : geekeeksLazyroarbestforall241569
Time Complexity: O(n),, where n is the length of the input string, because it needs to iterate over every character in the string to check if it’s a digit or not and for adding the digits at the end.
Auxiliary Space: O(n), because it creates a new string to store the separated digits and the characters that aren’t digits, and it also creates a variable to store digits.
Method 2 : Using join()
In this, we perform the task of extracting digits and ignoring them using separate comprehensions and then joining both. At the end, digit string is joined at end of actual string.
Python3
# initializing stringtest_str = 'geek2eeks4g1eek5sbest6forall9'# printing original stringprint("The original string is : " + str(test_str))# getting all numbersdig = ''.join(ele for ele in test_str if ele.isdigit())# getting all elements not digitres = ''.join(ele for ele in test_str if not ele.isdigit())# adding digits at endres += dig# printing resultprint("Strings after digits at end : " + str(res)) |
The original string is : geek2eeks4g1eek5sbest6forall9 Strings after digits at end : geekeeksLazyroarbestforall241569
Time Complexity: O(n), where n is the length of the string ‘test_str’.
Auxiliary Space: O(n), where n is the length of the string ‘test_str’.
Method 3: Without using any built-in method.
Python3
# initializing stringtest_str = 'geek2eeks4g1eek5sbest6forall9'# printing original stringprint("The original string is : " + str(test_str))digits="0123456789"# getting all numbers and removing digitsres = ''dig = ''for ele in test_str: if ele in digits: dig += ele else: res += ele# adding digits at endres += dig# printing resultprint("Strings after digits at end : " + str(res)) |
The original string is : geek2eeks4g1eek5sbest6forall9 Strings after digits at end : geekeeksLazyroarbestforall241569
Time Complexity: O(n)
Auxiliary Space: O(n)
Method 4: Using isnumeric() method
Python3
# initializing stringtest_str = 'geek2eeks4g1eek5sbest6forall9'# printing original stringprint("The original string is : " + str(test_str))# removing digitsres = ''dig = ''for ele in test_str: if ele.isnumeric(): dig += ele else: res += ele# adding digits at endres += dig# printing resultprint("Strings after digits at end : " + str(res)) |
The original string is : geek2eeks4g1eek5sbest6forall9 Strings after digits at end : geekeeksLazyroarbestforall241569
Method 5 : Using isalpha() method
Python3
#Python Program to move numbers to the end of the string# initializing stringtest_str = 'geek2eeks4g1eek5sbest6forall9'# printing original stringprint("The original string is : " + str(test_str))# removing digitsres = ''dig = ''for ele in test_str: if ele.isalpha(): res += ele else: dig += ele# adding digits at endres += dig# printing resultprint("Strings after digits at end : " + str(res)) |
The original string is : geek2eeks4g1eek5sbest6forall9 Strings after digits at end : geekeeksLazyroarbestforall241569
Time complexity: O(n), where n is the length of the input string test_str.
Auxiliary space: O(n), where n is the length of the input string test_str.
Method 6 : Using filter()+join()+list()+lambda functions
Python3
# initializing stringtest_str = 'geek2eeks4g1eek5sbest6forall9'# printing original stringprint("The original string is : " + str(test_str))# getting all numbersdig = ''.join(list(filter(lambda x: x.isdigit(), test_str)))# getting all elements not digitres = ''.join(list(filter(lambda x: not x.isdigit(), test_str)))# adding digits at endres += dig# printing resultprint("Strings after digits at end : " + str(res)) |
The original string is : geek2eeks4g1eek5sbest6forall9 Strings after digits at end : geekeeksLazyroarbestforall241569
Time Complexity:O(N)
Auxiliary Space: O(N)
Method 7 : Using ord() method
Python3
#Python Program to move numbers to the end of the string# initializing stringtest_str = 'geek2eeks4g1eek5sbest6forall9'# printing original stringprint("The original string is : " + str(test_str))# removing digitsres=""dig=""for i in test_str: if ord(i)>=48 and ord(i)<=57 : dig+=i else: res+=ires+=dig# printing resultprint("Strings after digits at end : " + str(res)) |
The original string is : geek2eeks4g1eek5sbest6forall9 Strings after digits at end : geekeeksLazyroarbestforall241569
Time Complexity:O(N)
Auxiliary Space: O(N)
Method 8 : Using Regular expressions:
Python3
import reinputString = 'geek2eeks4g1eek5sbest6forall9'# printing the input stringprint("Input string: ", inputString)# Extracting digits using regular expressionsdigits = ''.join(re.findall('\d', inputString))# Removing digits using regular expressionsresultantString = re.sub('\d', '', inputString)# Concatenating/adding digits at the end of the resultant stringresultantString += digitsprint("Resultant string after adding digits at the end:\n", resultantString)#This code is contributed by Jyothi pinjala |
Input string: geek2eeks4g1eek5sbest6forall9 Resultant string after adding digits at the end: geekeeksLazyroarbestforall241569
Time Complexity: O(N)
Auxiliary Space: O(N)
Method 9 : Using translate() function:
Python3
# initializing stringtest_str = 'geek2eeks4g1eek5sbest6forall9'# printing original stringprint("The original string is : " + test_str)# getting all numbers and removing digitsimport stringtable = str.maketrans('', '', string.digits)res = test_str.translate(table)dig = ''.join([char for char in test_str if char.isdigit()])# adding digits at endres += dig# printing resultprint("Strings after digits at end : " + res) |
The original string is : geek2eeks4g1eek5sbest6forall9 Strings after digits at end : geekeeksLazyroarbestforall241569
Time Complexity: O(N)
Auxiliary Space: O(N)
