Merging Dictionaries in Python

Merging Dictionaries

• Use the update() method to merge one dictionary into another, modifying the first dictionary.
• The ** unpacking operator can also be used: merged_dict = {**dict1, **dict2}.
• In Python 3.9 and later, the | operator allows merging: merged_dict = dict1 | dict2.

Purpose of 'self' in a Class

• 'self' is a reference to the instance of the class, allowing access to instance variables and methods.
• It differentiates between instance attributes and local variables within methods.

Creating a List of Squares

• Use a list comprehension: squares = [x**2 for x in range(1, 11)] to generate a list of squares from 1 to 10.

Output of print('abc' * 3)

• Output is 'abcabcabc', which repeats the string 'abc' three times.

Getting Current Date and Time

• Use the datetime module: from datetime import datetime; current_time = datetime.now() to retrieve the current date and time.

Difference Between '==' and 'is'

• '==' checks for value equality, determining if two variables have the same value.
• 'is' checks for identity, determining if two variables reference the same object in memory.

Swapping Two Variables

• One can swap two variables without a third variable through tuple unpacking: a, b = b, a.

Removing the Last Element from a List

• Use the pop() method: list.pop() removes and returns the last element of the list. Alternatively, use del list[-1] to remove without returning.

Purpose of the pass Statement

• The pass statement serves as a placeholder in code, allowing for syntactically correct empty blocks, such as in functions or loops that have not been implemented.

Sorting a List of Numbers

• Use the sort() method to sort the list in place, or sorted(list) to return a new sorted list. Both methods arrange the list in ascending order by default.