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A list is a collection which is ordered and changeable that allows duplicate members. Lists are created using square brackets.

List

Sample Codeeven_numbers = [2,4,6,8,10]
print(even_numbers)
print(len(even_numbers)) # Number Of Items In List
duplicate_list = [2,4,6,8,10,2,4,6,8,10]
print(duplicate_list)
print(duplicate_list[1]) # Access List Item By Index Number
print(duplicate_list[2:5]) # Range Of Indexes
even_numbers[5] = 12 # Change Item Value By Index Number
print(even_numbers)
even_numbers.append(14) # Add Item To End
print(even_numbers)
even_numbers.insert(1, 2) # Insert Item Value At Index Number
print(even_numbers)
even_numbers.remove(2) # Remove Item Value
print(even_numbers)
even_numbers.pop(1) # Pop Item At Index Number
print(even_numbers)
del even_numbers.pop[1] # Remove Item At Index Number
print(even_numbers)
even_numbers.clear() # Remove All Items
print(even_numbers)
even_numbers.sort() # Sort All Items In Ascending Order
print(even_numbers)
even_numbers.reverse() # Sort All Items In Reverse Order
print(even_numbers)
copied_list = even_numbers.copy() # Make A Copy
print(copied_list)
list1 = [“John”, “Jake”]
list2 = even_numbers.copy()
list3 = list1 + list2 # Join Two Lists
list1.extend(list2) # Add Elements From One List
print(list1)
print(list3)
print(list1.count(“John”)) # Returns Number Of Times The Value “John” Appears
print(list1.index(“John”)) # Returns Index Of First Time The Value “John” Appears

Table : Common Functions For Manipulating Lists

An array specifies a variable that can be indexed as a list in rows and columns. The first index is zero as is common in most programming languages.

Python does not have an array data type. Instead the data type list, tuple, set or dictionary can be used.

Python logical operators are used to combine conditional statements. Each operand is a conditional that can be evaluated to a true or false value. The value of the conditions determines the overall value of the operator or grouping.

Logical operators are use to control flow of the application. They are normally found as part of a control statement such as if and while.

Table : Logical Operators

Logical Operators

Sample Codenum1 = 5
num2 = 10
if ( num1 > 0 and num2 > 0 ):
	print(“Both AND conditions are true”)
else:
	print(“This condition grouping is false”)
if ( num1 > 0 or num2 > 0 ):
	print(“At least one OR condition is true”)
else:
	print(“Both conditions are false”)

Python increment operators are used to increment a variable’s value and decrement operators are used to decrement a variable’s value. Python does not support pre- and post-increment and decrement operators allowing for the increment or decrement of the value by one.

Table : Increment And Decrement Operators

Increment And Decrement Operators

Sample Codenum = 1
num += 1 # Increment By One
print(num1) # Displays 2
num -= 1 # Decrement By One
print(num1) # Displays 1

Comparison operators compare two values which can be numbers or strings.

Table : Comparison Operators

Comparison Operators

Sample Codename1 = “John”
name2 = James”
print(name1 == name2) # Displays False
print(name1 == 10) # Displays False
num1 = 12
num2 = 22
print(num1 > num2) # Displays False
print(num1 == 10) # Displays False

variables have the same naming convention where the variable is defined. Therefore arithmetic types are scalar types. Arrays (list, tuple and range) are aggregate types.

Table : Assignment Operators

Assignment Operators

Sample Codenum1 = 5
num2 = 3
num_equ = num1
num_add += num2
num_equ = num1
num_sub -= num2
num_equ = num1
num_mul *= num2
num_equ = num1
num_div /= num2
num_equ = num1
num_mod %= num2
num_equ = num1
num_flo //= num2
print(num_add) # Displays 8
print(num_sub) # Displays 2
print(num_mul) # Displays 15
print(num_div) # Displays 1.66
print(num_mod) # Displays 2
print(num_exp) # Displays 125
print(num_flo) # Displays 1

The arithmetic operators perform addition, subtraction, multiplication, division, exponentiation, floor division and modulus operations.

Table : Arithmetic Operators

Arithmetic Operators

Sample Codenum1 = 5
num2 = 3
num_add = num1 + num2
num_sub = num1 – num2
num_mul = num1 * num2
num_div = num1 / num2
num_mod = num1 % num2
num_exp = num1 ** num2
num_flo = num1 // num2
print(num_add) # Displays 8
print(num_sub) # Displays 2
print(num_mul) # Displays 15
print(num_div) # Displays 1.66
print(num_mod) # Displays 2
print(num_exp) # Displays 125
print(num_flo) # Displays 1

An operator is defined to behave like a function but is restricted to specific operations on variables and values.

Some of the operators in Python are arithmetic, assignment, comparison, increment, decrement and logical.

Python strings are surrounded by either single or double quotation marks.

String literal can be displayed with the built-in print function.

Stings

Sample Codestr1 = “Hello World!”
str2 = ‘Hello World!’
print (str1, str2)

Quotes can be used inside a string only if they do not match the quotes surrounding the string.

Quotes Inside Strings

Sample Codestr1 = “It’s easy”
str2 = “Call me ‘Johnny'”
str3 = ‘Call me “Johnny”‘
print(str1, str2, str3)

Assign a multiline string to a variable using 3 quotes.

Multiline Strings

Sample Codestr1 = “””This is a double quoted
multiple line string
spanning 3 rows.”””
str1 = ”’This is a single quoted
multiple line string
spanning 3 rows.”’
print(str1, str2)

Return a part of the string using the slice syntax. To slice a string, specify the start index and end index separated by a colon. The first character has index 0.

Slicing

Sample Codestr1 = “Hello, World!”
print (str1[2:5]) # Prints from position 2 to position 5
print(str1[:5]) # Prints  from position 0 to position 5
print(str1[2:]) # Prints from position 2 to the end
print(str1[-5:-2]) # Prints from position -5 to position -2

Table : Common Functions For Manipulating Strings

Strings can be combined using string concatenation via the plus “+” symbol

Concatenate Strings

Sample Codestr1 = “Hello”
str2 = “World”
str3 = str1 + str2
str4 = str1 + ” ” + str2
print(str3) # Displays HelloWorld
print(str4) # Displays Hello World

Strings and numbers can be combined using F-strings.

F-Strings Format Strings

Sample Codeage = 24
name = “John”
combined = f”My name is {name}, and I am {age} years old”
print(combined) 

Strings can be escaped using the backslash character “\”.

Table : Escape Characters

Escape Characters

Sample Codestr1 = “My name is \”Johnny\” but you can call me \”John\”.”
print(str1)

Booleans represent only 2 values, True or False. Any expression can be evaluated to get one of the two answers, True of False. Empty and zero values will be evaluated as False.

Boolean Values

Sample Codename = “John”
num1 = 5
num2 = 3
print(bool(name)) # Prints True
print(bool(num1)) # Prints True
print(num1 > num2) # Prints True
print(num1 == num2) # Prints False
print(num1 < num2) # Prints False
print(False) # Prints False
print(bool(None)) # Prints False
print(bool(0)) # Prints False
print(bool(“”)) # Prints False
print(bool(())) # Prints False
print(bool([])) # Prints False
print({}) # Prints False