Module 1 Python Basics

Question 1

What scientific computing libraries does Python have?

Answer 1

Pandas, NumPy, SciPy, and Matplotlib

Question 2

What scientific AI libraries does Python have?

Answer 2

Keras, Scikit-learn, Tensorflow, Pytorch

Question 3

Python can be used for Natural Language Processing (NLP), using the Natural Language Toolkit (NLTK) Yes or No?

Answer 3

Yes

Question 4

What is an Int?

Answer 4

A whole number (no decimals)

Question 5

What is a float?

Answer 5

A real number (Anything between integers ex: 0.8 is between 0 and 1)

Question 6

Changing Expression Types (Type Casting)

Answer 6

• You can convert (cast) an int to a float
• If the string contains an integer value you can convert it to an integer
• If we convert a string that contains a non-integer to an integer value, we get an error
• You can convert an int to a string
• You can convert a float to a string

Question 7

Data Types: Boolean

Answer 7

• Booleans can be True and False (remember to use uppercase T and F)
• Using the type command on a Boolean value we obtain the term bool (example: type(True): bool
• If we cast a Boolean True to an interger or float we obtain the number 1
• If we cast a Boolean False to an integer or float we obtain the number 0
• If we cast a 1 to a boolean bool(1)we get a true
• If we cast a 0 to a boolean bool(0) we get a false

Question 8

What is the type of the result of 6/2?

Answer 8

Float

Question 9

What is the type of the result of 6//2?

Answer 9

Int

• The double slashes stand for integer division

Question 10

Expressions and Variables

Answer 10

.

Question 11

Expressions

Answer 11

Expressions describe a type of operation that computers perform.

Question 12

Expressions are also…..

Answer 12

Operations that python performs

Question 13

Operands

Answer 13

Numbers in a mathematical equation

Question 14

What are the math symbols called?

Answer 14

operators

Question 15

Variables

Answer 15

• Can be used to store values
• Ex: x = 1
• The colon denotes the value of the variable

So now x:1 will give you 1

• We can assign a new value to the colon using the same assignment operator. The old value will be overwritten with the new value

Question 16

Variables (Part 2)

Answer 16

We can also store the results of expressions

• Ex: x = 43 + 60 + 16 + 41
• x will now store the sum of that expression
• x: (which will equal 160)
• To see the value of x in a Notebook, we can simply place it on the last line of a cell (simply type your variable (x) in any empty cell to see its value

Question 17

Strings Operations

Answer 17

.

Question 18

String

Answer 18

• Can be spaces or digits
• Can also be special characters
• We can bind or assign a string to another variable
• String are an ordered sequence (Ex: Michael, M =0, i=1, c=2, h=3, a=4, e=5, l=6)
• The index can be accessed for each letter with this command (Ex: variable_name[#]:
  You can also used negative indexing with strings. The last index will be given -1

Question 19

Strings:

Answer 19

Name = Michael Jackson

• Think of strings as a list or index
• You can bind a string to another variable
• Ex: Name[0:4] = Mich (Every value up to index 3)
• Ex: Name[8-12] = Jack (Every value starting at index 8 up to index 11)

Question 20

Strings,Slicing, and Stride

Answer 20

Name[::2]: “McalJcsn”
- the 2 indicates we select every second variable
- Incorporating slicing will look like this
- Ex: Name[0:5:2]: “Mca”
- you are returning to every second value up to index four
- Ex: Michael…….. Name[0:5:2]: Mca

Question 21

Strings,Slicing, and Stride (Continued)

Answer 21

• You can use the len command to obtain the length of the string
• Ex: len(“Michael Jackson”) Answer: 15
• You can combine strings with the addition symbols
• Name = (“Michael Jackson”)
• Statement = Name + (“is the best”)
• Statement = (“Michael Jackson is the best”)

You can replicate values of a string by multiplying it by the number of times you would like to replicate it.

Ex: 4*(“Michael Jackson”) = (“Michael Jackson Michael Jackson Michael Jackson Michael Jackson”)
- You cannot change the value of the string but you can create a new string

Question 22

Strings are Immutable

Answer 22

• \ represents the beginning of escape sequences
• Escape sequences represent strings that may be difficult to input.
• For example \n represents a new line
• Ex: print(“Michael Jackson”\n is the best”)
  This will be the output Michael Jackson (and then “is the best”) will be put on the new line
• \t represents a tab
• If you actually want to put a backslash in your string do \ to put in a singular backslash in your string
• Ex: print(“Michael Jackson \ is the best”)
• Ex: Michael Jackson \ is the best
  OR
• You could place an “r” in front of the string
• Ex: print(r”Michael Jackson is the best”)
• Michael Jackson \ is the best

Question 23

String Methods

Answer 23

One is converting lowercase characters to uppercase characters

A = “Thriller is the six studio album”
B =A.upper()
B:”THRILLER IS THE SIX STUDIO ALBUM”

A=’Michael Jackson is the best’
B=A.replace(‘Michael,’ ‘Janet’)
B: ‘Janet Jackson is the best’

Name = Michael Jackson

Name.find(‘el’): 5
Name.find(‘Jack’):8
————————————————————————-

• If the substring is not in the string, the output is -1.

Question 24

String interpolation (f-strings)

Answer 24

Introduced in Python 3.6, f-strings are a new way to format strings in Python. They are prefixed with ‘f’ and use curly braces {} to enclose the variables that will be formatted. For example:

1 name = “John”
2 age = 30
3 print(f”My name is {name} and I am {age} years old.”)

• This will output as —-> My name is John and I am 30 years old.

Question 25

F-strings are also able to evaluate expressions inside the curly braces, which can be very handy. For example:

Answer 25

1 x = 10
2 y = 20
3 print(f”The sum of x and y is {x+y}.”)

• This will be the output —-> The sum of x and y is 30.

Question 26

Raw String (r’’)

Answer 26

• In Python, raw strings are a powerful tool for handling textual data, especially when dealing with escape characters. By prefixing a string literal with the letter ‘r’, Python treats the string as raw, meaning it interprets backslashes as literal characters rather than escape sequences.

Question 27

Raw String (r’’) (Continued)

Answer 27

Regular string:

1 regular_string = “C:\new_folder\file.txt”
2 print(“Regular String:”, regular_string)

This will ouput
1 Regular String: C:
2 ew_folderile.txt

In the regular string regular_string variable, the backslashes (\n) are interpreted as escape sequences. Therefore, \n represents a newline character, which would lead to an incorrect file path representation.

Raw string:

1 raw_string = r”C:\new_folder\file.txt”
2 print(“Raw String:”, raw_string)

This will output

Raw String: C:\new_folder\file.txt

However, in the raw string raw_string, the backslashes are treated as literal characters. This means that \n is not interpreted as a newline character, but rather as two separate characters, ‘’ and ‘n’. Consequently, the file path is represented exactly as it appears.

Question 28

Seperator

Answer 28

• This is the delimiter at which the string will be split. If not provided, the default separator is any whitespace.

Question 29

Maxsplit

Answer 29

• This specifies the maximum number of splits to perform. If not provided, there is no limit on the number of splits.

Question 30

Split

Answer 30

Syntax

string.split(separator, maxsplit)

Question 31

RegEx

Answer 31

• RegEx (short for Regular Expression) is a tool for matching and handling strings.