Questions and Answers
How can you merge two dictionaries in Python?
What is the purpose of 'self' in a class?
How do you create a list of squares of numbers from 1 to 10 in Python?
What is the output of print('abc' * 3)
?
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How can you get the current date and time in Python?
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What is the difference between '==' and 'is' in Python?
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How do you swap two variables in Python without using a third variable?
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How can you remove the last element from a list in Python?
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What is the purpose of the pass
statement in Python?
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How can you sort a list of numbers in ascending order?
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Study Notes
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, usedel 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, orsorted(list)
to return a new sorted list. Both methods arrange the list in ascending order by default.
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Description
This quiz explores various methods to merge two dictionaries in Python. Test your knowledge on the syntax and different approaches available to accomplish this task successfully.