Check Order of Characters in String Using OrderedDict in Python

When it is required to check the order of the character in the string, the ‘OrderedDict’ method can be used.

Below is the demonstration of the same −

Example

 Live Demo

from collections import OrderedDict
def check_order(my_input, my_pattern):
   my_dict = OrderedDict.fromkeys(my_input)
   pattern_length = 0
   for key,value in my_dict.items():
      if (key == my_pattern[pattern_length]):
         pattern_length = pattern_length + 1

      if (pattern_length == (len(my_pattern))):
         return 'The order of pattern is correct'

   return 'The order of pattern is incorrect'

my_input = 'Hi Mark'
input_pattern = 'Ma'
print("The string is ")
print(my_input)
print("The input pattern is ")
print(input_pattern)
print(check_order(my_input,input_pattern))

Output

The string is
Hi Mark
The input pattern is
Ma
The order of pattern is correct

Explanation

• The required packages are imported.

• A method named ‘check_order’ is defined, that takes two parameters.

• An ordered dictionary is created using the ‘fromkeys’ method.

• The length of pattern is initialized to 0.

• If the key is equal to the pattern, then the length of pattern is incremented.

• If the length of pattern is same as the current length, it means the order is right, else the order is wrong.

• Relevant messages are displayed as output on the console.