OrderedDict Module in Python with Examples

In this article, we will read about the Python Ordereddict module, and will see the difference in its execution with different attributes through codes.

Covering its various functions and getting well along with its attributes will be a major focus of this article, so let’s get started.

What is OrderedDict in Python?

Ordereddict is a method of insertion of the loop variables in an empty list in python.

Ordereddict module is predefined in the python library, and hence needs to be imported in the code before its usage.

The mutable lists work as an ordered dict in a code for any arbitrary constant value in the code. The coder as well as the user can define such lists in runtime of the code.

OrderedDict Example in Python:

thisistech = {} 
thisistech['woah'] = 1
thisistech['why'] = 2
thisistech['hey'] = 3
thisistech['hello'] = 4
  
for key, value in thisistech.items(): 
    print(key, value) 
  
print("ordered dict is this") 

Output:

Python OrderedDict Syntax

OrderedDict in python is a collection of multiple lists, but the coder imports it from the module ‘collection’ before any execution.

>>> from collections import OrderedDict

Key value Change: This signifies to the modulation in the change of the main key in the list. It can be simply done by inserting a new element in the place of the old one by import function.

Python OrderedDict Example:

from collections import OrderedDict 
print("Before the execution") 
thisistech= OrderedDict() 
thisistech['woah'] = 0
thisistech['why'] = 2
thisistech['here'] = 3
thisistech['how'] = 4
for key, value in thisistech.items(): 
    print(key, value) 
  
print("after execution") 
thisistech['yayay'] = 90
for key, value in thisistech.items(): 
    print(key, value) 

Output:

Deletion and Re-Inserting: It is common that at places the coder needs to delete the previous value and insert the new one. Or probably the already defined value if wrongly inserted may need to get deleted. This can be simply done by the delete function in the list.

Code:

from collections import OrderedDict 
  
print("Before execution:\n") 
thisistech = OrderedDict() 
thisistech['woah'] = 1
thisistech['where'] = 2
thisistech['when'] = 3
thisistech['why'] = 4
  
for key, value in thisistech.items(): 
    print(key, value) 
  
print("\nAfter deletion:\n") 
thisistech.pop('when') 
for key, value in thisistech.items(): 
    print(key, value) 
  
print("\nAfter re-inserting execution:\n") 
thisistech['when'] = 3
for key, value in thisistech.items(): 
    print(key, value)

Output:

OrderedDict Reverse Iteration

The values in a code can be displayed in reverse order on the final output. And this is best done by reverse iteration in the code, for example:

OrderedDict Reverse Iteration Example in Python:

thisistech=['w','l','k']
for r in reversed(thisistech):
    print(r)

Output:

Changing the Value of a Specified Key

When the value of a specified key is changed by the user, the numbering of keys does not change. This is simply done by manipulating one list’s elements in the other list.

Equality

This basically compares the two lists element wise, before compiling them in a final list. The two matched elements are always taken as one only in the final list.

Code:

def thisistech():
    
   thisistech['p']=1
   thisistech['q']=2
print(thisistech)

Output:

Python Popitem ()

The popItem() method in Python may take 0 or 1 argument that means on and off in binary language. If a passed argument is a null set then, the last element is assumed to be true by default.

Python OrderedDict Example:

thisistech=OrderedDict()
thisistech['d']=4
thisistech['e']=5
print(d)

Output:

Conclusion

In this article we’ve read about the functions, attributes and methods of defaultdict module in python. Default dict module is mostly used in program oriented codes, or the reports and generally in technical analysis also. But it needs good practice for applicable usage also. Happy pythonning!