General Python

Question 1

What function allows you to check whether or not a variable is part of a specific class?

Answer 1

isinstance() is the function to check if a variable to check the class.

> > > number = 23
isinstance(number, int)
True
isinstance(number, str)
False
isinstance(number, float)
False

Question 2

What function can you use to find the highest value in an iterable such as a list, a tuple, or a dictionary (for which it returns the maximum key).?

Answer 2

The max() function returns the highest value.

> > > numbers = [1, 2, 3, 4]
max(numbers)
4

> > > numbers = (1, 2, 3, 4)
max(numbers)
4

> > > points = {34: ‘John’, 25: ‘Kate’, 70: ‘Jane’}
max(points)
70

Question 3

What process removes duplicates from a list?

Answer 3

Converting from a list to a set removes duplicate elements.

Question 4

How do you convert a list to a set?

Answer 4

> > > animals = [‘tiger’, ‘tiger’, ‘lion’, ‘giraffe’, ‘lion’]
set(animals)
{‘tiger’, ‘lion’, ‘giraffe’}

Question 5

Why would you convert a list into a tuple?

Answer 5

Converting a list into a tuple can be useful when you need to create an immutable collection of elements from an existing list. Immutable means that the data structure cannot be modified.

Question 6

How do you convert a list into a tuple?

Answer 6

> > > animals = [‘tiger’, ‘lion’, ‘giraffe’, ‘lion’]
tuple(animals)
(‘tiger’, ‘lion’, ‘giraffe’, ‘lion’)

Question 7

What are the key Set operations?

Answer 7

The key set operations are union, intersection and difference.

Question 8

What does union do?

Answer 8

set1 = {1, 2, 3}
set2 = {3, 4, 5}
union = set1 | set2

> > {1, 2, 3, 4, 5}

Question 9

What does intersection do?

Answer 9

set1 = {1, 2, 3}
set2 = {3, 4, 5}
intersection = set1 & set2

> > {3}

Question 10

What does difference do?

Answer 10

set1 = {1, 2, 3}
set2 = {3, 4, 5}
difference = set1 - set2

> > {1,2}

Question 11

What are *args and **kwargs?

Answer 11

*args is used to pass positional arguments to a function via a tuple.

**kwargs is used to pass keyword arguments to a function via a dictionary.

Calling the function with different arguments
example_function(1, 2, 3, name=”Alice”, age=30)

Positional arguments (*args):
1
2
3

Keyword arguments (**kwargs):
name: Alice
age: 30

Question 12

What is the basic syntax of a List comprehension?

Answer 12

The basic syntax of a list comprehension is:

[expression for item in iterable if condition]

Question 13

What does “python -m” do?

Answer 13

The -m flag in Python allows you to run a module as a script. When you use python -m <module>, Python will locate the specified module and run it as if it were a standalone script, rather than simply importing it.</module>

Question 14

How do you check if any python packages are outdated?

Answer 14

To check which packages in your virtual environment are outdated, you can run:

pip list –outdated

Question 15

How do you update any out of date packages?

Answer 15

To update all outdated packages:

pip install –upgrade <package_name></package_name>

Question 16

How do you create a local git repo?

Answer 16

Inside your project folder, run the following command to initialize a Git repository:
git init

Question 17

How do you add the files that you want git to track?

Answer 17

Add the files you want to track to Git using:
git add .

This stages all the files in your project for committing. You can also add specific files by replacing . with the file name.

Question 18

How do you commit the staged files in git?

Answer 18

Commit the staged files with a message describing the changes:

git commit -m “Initial commit”

Question 19

How do you push from your local repo to a remote repo?

Answer 19

If you want to back up your code to a platform like GitHub, you can create a remote repository and link it to your local one:

git remote add origin <repository_url></repository_url>

Afterward, you can push your code to the remote:
git push -u origin master

Question 20

How would you list all previous commits?

Answer 20

To view the commit history of your repository, use the following command:

git log

This command will show a detailed log of commits, starting from the most recent. Each commit will be listed with the following information:

Commit hash: A long alphanumeric string identifying the commit.
Author: The name of the person who made the commit.
Date: The date and time the commit was made.
Commit message: A description of what was changed.
For a more concise view, use:

git log –oneline

This will show the commits in a simplified format with just the commit hash and message, making it easier to read through the commit history.

Question 21

How would you rollback to a specific commit?

Answer 21

Soft Reset: Keeps your changes in the working directory, but resets the commit history.

git reset –soft <commit-hash></commit-hash>

This will undo commits but keep the changes staged, so you can re-commit them.

Mixed Reset (default): Keeps your changes in the working directory but unstages them.
git reset <commit-hash></commit-hash>

This will undo the commits and move the changes to your working directory without staging them.

Hard Reset: Resets the commit history and removes all changes in the working directory (use with caution).

git reset –hard <commit-hash></commit-hash>