public/subjects/devops/merge_two/README.md

Merge two

One very useful data structure in Python are the dictionaries, in this exercise we will start to familiarize and use them.

Instructions

Create a file merge_two.py which will have a function named merge_two(). This function will accept one dictionary. It will prompt the user to create a new dictionary asking for keys and values. The function will always convert the values into integers.

As a return it will create a third one which will be the merge of the two dictionaries and return it as a serialized JSON string.

If the key entered by the user is exit the function will stop asking for new key/values pairs and proceed to generate the desired output.

Here is the prototype of the function:

def merge_two(first_dict):
    # this is a function,
    # write your code here

Usage

Here is a possible code to test your function. Put it in another file (ex: test.py):

from merge_two import merge_two

first = {
    "Bob": 36,
    "Louise": 23,
    "Lea": 34
}

print(merge_two(first))

Run your test file with the following command:

$ python3 test.py
Add a new entry:
key: Louise
value: 44
Add a new entry:
key: Romolo
value: 30
Add a new entry:
key: Lea
value: 22
Add a new entry:
key: exit
{"Bob": 36, "Louise": 44, "Lea": 22, "Romolo": 30}
$

Hints

• If a key is repeated in both dictionaries the value retained will be the last one.

• There are different ways to merge dictionaries, take the time to understand the differences in between those techniques and try more than one technique to better retain it.

• Add import json to use the standard functions for JSON manipulation.

• Use the function input() to read from stdin and int() to convert the value to a number.

Your solution will be tested only for valid inputs (all the values will be convertible to int).

References

• Merging dictionaries in Python
• JSON library in Python
• Function input() in Python