Python Program to move numbers to the end of the string

In this article, we will learn a python program to move numbers to the end of the string.

Methods Used

The following are the various methods to accomplish this task ?

• Using isdigit() and for loop

• Using isdigit() and join() functions

• Without using any built-in functions

• Using isnumeric() function

• Using isalpha() function

Example

Assume we have taken an input string. We will now move all the numbers contained in an input string to the end of the string using the above methods.

Input

inputString = 'hello5691 tutorialspoint1342' 

Output

Resultant string after adding digits at the end: hello tutorialspoint56911342 

Here all the numbers 56911342 contained in an input string are moved to the end of the string.

Method 1: Using isdigit() and for loop

Algorithm (Steps)

Following are the Algorithm/steps to be followed to perform the desired task -.

• Create a variable to store the input string.

• Create an empty string to store the resultant string.

• Create another empty string to store all digits.

• Use the for loop to traverse through each character of an input string.

• Apply isdigit() function to the current character to check whether the current character is a digit or not using an if conditional statement.

• Add that current character to a digits string, if the condition is true.

• Else add that character to the above resultant string.

• Use the + operator(string concatenation) to add digits at the end of the resultant string.

• Print the resultant string after adding digits at the end of the string.

Example

The following program returns a string after adding all the digits to the end of an input string using for loop and isdigit() function -

# input string inputString = 'hello5691 tutorialspoint1342' # printing the input string print("Input string: ", inputString) # storing resultant string resultantString = '' # storing all digits digits = '' # traversing through each character of the input string for c in inputString: # checking whether the current character is a digit or not if c.isdigit(): # add that character to a digits string, if the condition is true digits += c else: # else add that character to the above resultant string resultantString += c #concatenating/adding digits at the end of the resultant string resultantString += digits # printing resultant string after adding digits at the end print("Resultant string after adding digits at the end:\n", resultantString) 

Output

On executing, the above program will generate the following output -

Input string: hello5691 tutorialspoint1342 Resultant string after adding digits at the end: hello tutorialspoint56911342 

Method 2: Using isdigit() and join() functions

join() function ? join() is a string function in Python that is used to join elements of a sequence that are separated by a string separator. This function connects sequence elements to convert to a string.

Example

The following program returns a string after adding all the digits to the end of an input string using isdigit() and join() functions -

# input string inputString = 'hello5691 tutorialspoint1342' # printing the input string print("Input string: ", inputString) #traversing through each character of a string and getting all digits digits = ''.join(c for c in inputString if c.isdigit()) # getting all other characters(not digits) resultantString = ''.join(c for c in inputString if not c.isdigit()) # concatenating/adding digits at the end of the resultant string resultantString += digits print("Resultant string after adding digits at the end:\n", resultantString) 

Output

Input string: hello5691 tutorialspoint1342 Resultant string after adding digits at the end: hello tutorialspoint56911342 

Method 3: Without using any built-in functions.

Example

The following program returns a string after adding all the digits to the end of an input string Without using any built-in functions -

# input string inputString = 'hello5691 tutorialspoint1342' # printing the input string print("Input string: ", inputString) # storing all digits digits_str = "0123456789" # storing all characters except digits resultantString = '' # storing all digits of an input string resultDigits = '' # traversing through each character of a string for c in inputString: # checking whether that current character is in the above digits string if c in digits_str: # adding that character to the resultDigits string resultDigits += c else: # else adding that character to the resultant string resultantString += c # concatenating/adding digits at the end of the resultant string resultantString += resultDigits print("Resultant string after adding digits at the end:\n", resultantString) 

Output

Input string: hello5691 tutorialspoint1342 Resultant string after adding digits at the end: hello tutorialspoint56911342 

Method 4: Using isnumeric() function

isnumeric() function ? Returns True if all the characters in a string are numeric (0-9), else returns False.

Example

The following program returns a string after adding all the digits to the end of an input string using isnumeric() function -

# input string inputString = 'hello5691 tutorialspoint1342' # printing the input string print("Input string: ", inputString) # storing all characters except digits resultantString = '' # storing all digits digits = '' # traversing through each character of an input string for c in inputString: # checking whether the current character is a digit if c.isnumeric(): # adding that digit to the above digits string digits += c else: # else adding that character to the resultantString resultantString += c # concatenating/adding digits at the end of the resultant string resultantString += digits print("Resultant string after adding digits at the end:\n", resultantString) 

Output

Input string: hello5691 tutorialspoint1342 Resultant string after adding digits at the end: hello tutorialspoint56911342 

Method 5: Using isalpha() function

isalpha() function ? Returns True if all the characters are aplhabets(a-z), else returns False.

Example

The following program returns a string after adding all the digits to the end of an input string using isalpha() function -

# input string inputString = 'hello5691 tutorialspoint1342' # printing the input string print("Input string: ", inputString) # storing all characters except digits resultantString = '' # storing all digits digits = '' # traversing through each character of a string for c in inputString: if(c!=' '): # checking whether current character is an alphabet if c.isalpha(): # adding that character to the resultantString resultantString += c else: # else adding that digit to the digits digits += c # concatenating/adding digits at the end of the resultant string resultantString += digits print("Resultant string after adding digits at the end:\n", resultantString) 

Output

Input string: hello5691 tutorialspoint1342 Resultant string after adding digits at the end: hello tutorialspoint56911342 

Conclusion

In this article, we covered 5 different methods for moving numbers to the end of a string. The same program was also implemented by us without utilizing the built-in functions.