Python Program for Sign Change

In the previous article, we have discussed Python Program to Find the Previous Armstrong Number
Given a String and the task is to change the ‘+’ sign into ‘-‘ and vice versa for a given string.

Examples:

Example1:

Input:

Given String = "  --btech++geeks-- "

Output:

The given string { --btech++geeks-- } after changing the '+' sign into '-' and vice versa = ++btech--geeks++

Example2:

Input:

Given String = "--1++2--3+"

Output:

The given string { --1++2--3+ } after changing the '+' sign into '-' and vice versa = ++1--2++3-

Program for Sign Change in Python

Below are ways to change the ‘+’ sign into ‘-‘ and vice versa for a given string :

Using For Loop (Static Input)
Using For loop (User Input)

Method #1: Using For Loop (Static Input)

Approach:

Give the string as static input and store it in a variable.
Take an empty string say “new_str” and store it in another variable.
Loop in the given string using the for loop.
Inside the loop, check if the iterator value is equal to ‘+’ sign using the if conditional statement.
If it is true, then concatenate the ‘-‘ sign with the new_str and store it in the same variable new_str.
Check if the iterator value is equal to the ‘-‘ sign using the elif conditional statement.
If it is true, then concatenate the ‘+’ sign with the new_str and store it in the same variable new_str.
Else concatenate the iterator value to the new_str and store it in the same variable new_str.
Print the given string after changing the ‘+’ sign into ‘-‘ and vice versa.
The Exit of the program.

Below is the implementation:

# Give the string as static input and store it in a variable.
gvn_str = "32--1++4"
# Take an empty string say "new_str" and store it in another variable.
new_str = ""
# Loop in the given string using the for loop.
for itr in gvn_str:
  # Inside the loop, check if the iterator value is equal to '+' sign using the if
    # conditional statement.
    if(itr == "+"):
        # If it is true, then concatenate the  '-' sign with the new_str and store it in the
        # same variable new_str.
        new_str += "-"
# Check if the iterator value is equal to the '-' sign using the elif conditional statement.
    elif(itr == "-"):
      # If it is true, then concatenate the  '+' sign with the new_str and store it in the
        # same variable new_str.
        new_str += "+"
    else:
     # Else concatenate the iterator value to the new_str and store it in the same variable new_str.
        new_str += itr
# Print the given string after changing the '+' sign into '-' and vice versa.
print("The given string {", gvn_str,
      "} after changing the '+' sign into '-' and vice versa =", new_str)

Output:

The given string { 32--1++4 } after changing the '+' sign into '-' and vice versa = 32++1--4

Method #2: Using For loop (User Input)

Approach:

Give the string as user input using the input() function and store it in a variable.
Take an empty string say “new_str” and store it in another variable.
Loop in the given string using the for loop.
Inside the loop, check if the iterator value is equal to ‘+’ sign using the if conditional statement.
If it is true, then concatenate the ‘-‘ sign with the new_str and store it in the same variable new_str.
Check if the iterator value is equal to the ‘-‘ sign using the elif conditional statement.
If it is true, then concatenate the ‘+’ sign with the new_str and store it in the same variable new_str.
Else concatenate the iterator value to the new_str and store it in the same variable new_str.
Print the given string after changing the ‘+’ sign into ‘-‘ and vice versa.
The Exit of the program.

Below is the implementation:

# Give the string as user input using the input() function and
# store it in a variable.
gvn_str = input("Enter some random String = ")
# Take an empty string say "new_str" and store it in another variable.
new_str = ""
# Loop in the given string using the for loop.
for itr in gvn_str:
  # Inside the loop, check if the iterator value is equal to '+' sign using the if
    # conditional statement.
    if(itr == "+"):
        # If it is true, then concatenate the  '-' sign with the new_str and store it in the
        # same variable new_str.
        new_str += "-"
# Check if the iterator value is equal to the '-' sign using the elif conditional statement.
    elif(itr == "-"):
      # If it is true, then concatenate the  '+' sign with the new_str and store it in the
        # same variable new_str.
        new_str += "+"
    else:
     # Else concatenate the iterator value to the new_str and store it in the same variable new_str.
        new_str += itr
# Print the given string after changing the '+' sign into '-' and vice versa.
print("The given string {", gvn_str,
      "} after changing the '+' sign into '-' and vice versa =", new_str)

Output:

Enter some random String = btech++--geeks+++--
The given string { btech++--geeks+++-- } after changing the '+' sign into '-' and vice versa = btech--++geeks---++

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