היכרות עם פייתון

# Comments in python
# With # at the beginning of the line.
"""
Starting a multi line
comments
"""

print(2+2)        # prints 4
print(10 - 5)     # prints 5
print(4 * 8)      # prints 32
print(2 / 5)      # prints 0.4
print(8 % 4)      # remainder when 8 is divided by 4, prints 0
print(8 % 3)      # remainder when 8 is divided by 3, prints 2
print(2 ** 4)     # 2 * 2 * 2 * 2, prints 16
print(3 ** 2)     # 3 * 3, prints 9

age = 30
age += 10
# Now age is 40

first_name = "Dan"
age = 30

first_name = 'John'
last_name = "Doe"

first = "Hello "
second = "World"
long_result = first + second + "!"
# Output: Hello World!

sentence = "split this string on whitespace into individual words"
print(sentence.split())

todos = 'Finish Assignment,Work on Python Lab,Watch Movie,Go to Grocery Store'
# split todos on a specific character i.e. comma ,
print(todos.split(','))

# Transforming a string.
# There are more transformation functions.
######################################
string = "ConvErT ALL tO LoWErCASe"
print(string.lower())
#Output: convert all to lowercase

# Formating string - adding variables
######################################
open_string = "Sammy loves {}."
print(open_string.format("open source"))
# Output: Sammy loves open source.

print("Sammy the {1} has a pet {0}!".format("shark", "pilot fish"))
# Output: Sammy the pilot fish has a pet shark!

# String length
######################################
open_source = "Sammy contributes to open source."
print(len(open_source))
# Output: 33

# Joining strings
######################################
print(",".join(["sharks", "crustaceans", "plankton"]))
# Output: sharks,crustaceans,plankton

# Replace substring with another
######################################
balloon = "Sammy has a balloon."
print(balloon.replace("has","had"))
# Output: Sammy had a balloon.

operand_one = 30
operand_two = 7
result = operand_one / operand_two # 30 / 7 = 4.285714285714286
print(result)

value_a = True
value_b = False
value_c = True
value_d = False

print(value_a and value_b) # True and False will print False
print(value_a and value_c) # True and True will print True
print(value_a or value_d) # True or False will print True
print(value_b or value_d) # False or False will print False
print(not value_d) # not False will print True

grades = 85
attendance = 95
has_plagiarized = False
print(not has_plagiarized)

successfully_graduated = (grades > 70) and (attendance > 90) and (not has_plagiarized)
print(successfully_graduated)

# grades is a list that contains a collection of grades that are whole numbers
grades = [65, 55, 95, 70, 82, 100, 63, 89, 93]
# Woody Allen movies
woody_allen_movies = ['A Rainy Day In New York', 
    'Cafe Society', 
    'Whatever Words', 
    'Blue Jasmine', 
    'Manhattan']
# 3x3 matrix created using list
matrix = [[1,2,3], [4,5,6], [7,8,9]]

grades = [65, 55, 95, 70, 82, 100, 63, 89, 93]
new_grades = grades + [65, 55, 95]
print(new_grades )

grades = [65, 55, 95, 70, 82, 100, 63, 89, 93]
grades.append(100)
print(grades)
# Output: [65, 55, 95, 70, 82, 100, 63, 89, 93, 100]

grades = [65, 55, 95, 70, 82, 100, 63, 89, 93]
 
# Removes the first occurance of 55
shopping_line.remove(55)
print(grades)

# Output: [65, 95, 70, 82, 100, 63, 89, 93]

grades = [55, 55, 95, 70, 82, 100, 63, 89, 93]
numGrades = grades.count(55)

print(numGrades)
# Output: 2

grades = [55, 55, 95, 70, 82, 100, 63, 89, 93]
size = len(grades)
print(size) 
# Output: 9

grades = [65, 55, 95, 70, 82, 100, 63, 89, 93]
grades.sort()
print(grades)
# Output: [55, 63, 65, 70, 82, 89, 93, 95, 100]

grades = [65, 55, 95, 70, 82, 100, 63, 89, 93]

# Pop the last element
removed_element = grades.pop()

print(grades)
print(removed_element)

# Output:
# [65, 55, 95, 70, 82, 100, 63, 89]
# 93

# Pop the element 100
grades.pop(5)
print(grades)

# Output:
# [65, 55, 95, 70, 82, 63, 89]

grades = [65, 55, 95, 70, 82, 100, 63, 89, 93]

# access grade 100 at index 5 from grades list
print(grades[5])
# Output: 100

# access 'Cafe Society' from woody_allen movies list at index 1
print(woody_allen_movies[1])
# Output: Cafe Society

# access row [4,5,6] from matrix list at index 1
print(matrix[1])
# Output: [4,5,6]

# access row [4,5,6] from matrix available at index 1 & print number 6
# at index 2 in the same row
print(matrix[1][2])
# Output: 6

# access grade 100 at index -4 (4th from the end) from grades list
print (grades[-4])
# Output: 100

# access first four grades from grades list
print(grades [0:4])
# Output: [65, 55, 95, 70]

# delete grades 55 & 95 from list grades
del grades [1:3]
print(grades)
# Output: [65, 70, 82, 100, 63, 89, 93]

My_dict = {key: value, anotherKey: anotherValue}

# create a dictionary using curly brackets called john
# that stores name, phone, email, course and address
john = {'name': 'John', 
   'phone': 1234567890, 
   'email': 'john.doe@gmail.com', 
   'course: Python v3', 
   'address': '123 Front St City Country'}
print(john)

# create a dictionary using dict() called adam 
# that stores name, phone, email, course
adam = dict ({'name': 'Adam', 'phone': 1234567890, 'email': 'adam.smith@email.com',
'course': 'Python v3'})
print(adam)

john = {'name': 'John', 
   'phone': 1234567890, 
   'email': 'john.doe@gmail.com', 
   'course: Python v3', 
   'address': '123 Front St City Country'}

print(john['name'])
# Output: John
print(john['email'])
# Output: john.doe@gmail.com

john = {'name': 'John', 
   'phone': 1234567890, 
   'email': 'john.doe@gmail.com', 
   'course: Python v3', 
   'address': '123 Front St City Country'}

john['phone'] = 9876543210
print(john)
# Output: {'name': 'John', 'phone': 9876543210, 'email': 'john.doe@gmail.com', 'course': 'Python v3', 'address': '123 Front St City Country'}

john = {'name': 'John', 
   'phone': 1234567890, 
   'email': 'john.doe@gmail.com', 
   'course: Python v3', 
   'address': '123 Front St City Country'}

# delete address for john
john.pop('address')
print(john)
# Output: {'name': 'John', 'phone': 1234567890, 'email': 'john.doe@gmail.com', 'course': 'Python v3'}

john = {'name': 'John', 
   'phone': 1234567890, 
   'email': 'john.doe@gmail.com', 
   'course: Python v3', 
   'address': '123 Front St City Country'}

del john

# movies to watch for john
john_movies_wishlist = {'Titanic', 'Die Hard', 'Pulp Fiction', 'Forrest Gump', 'Parasite', 'Die Hard'}
# movies to watch for adam
adam_movies_wishlist = {'Psycho', 'The Lion King', 'Titanic', 'Parasite', 'Gladiator', 'Coco'}

# note: duplicate items from a set are automatically removed
print(john_movies_wishlist)
# Output: {'Parasite', 'Die Hard', 'Pulp Fiction', 'Forrest Gump', 'Titanic'}

# note: items do not appear in the same order as written
print(adam_movies_wishlist)
# Output: {'Parasite', 'Gladiator', 'Psycho', 'The Lion King', 'Titanic', 'Coco'}

# movies to watch for john
john_movies_wishlist = {'Titanic', 'Die Hard', 'Pulp Fiction', 'Forrest Gump', 'Parasite', 'Die Hard'}
# movies to watch for adam
adam_movies_wishlist = {'Psycho', 'The Lion King', 'Titanic', 'Parasite', 'Gladiator', 'Coco'}

# movies in John’s wishlist but not Adam’s
print(john_movies_wishlist - adam_movies_wishlist)
# Output: {'Pulp Fiction', 'Die Hard', 'Forrest Gump'}

# movies in either John's wishlist or Adam's wishlist or in both wishlists
print(john_movies_wishlist | adam_movies_wishlist)
# Output: {'Coco', 'Parasite', 'Gladiator', 'Titanic', 'Pulp Fiction', 'The Lion King', 'Forrest Gump', 'Psycho', 'Die Hard'}

# movies in both John's wishlist and Adam's wishlist
print(john_movies_wishlist & adam_movies_wishlist)
# Output: {'Titanic', 'Parasite'}

# movies in either John's wishlist or Adam's wishlist but not in both
print(john_movies_wishlist ^ adam_movies_wishlist)
# Output: {'Coco','Gladiator', 'The Lion King', 'Pulp Fiction', 'Forrest Gump', 'Psycho', 'Die Hard'}

# create a tuple of first five odd numbers
odd_numbers = (1, 3, 5, 7, 9)

print(odd_numbers)
(1, 3, 5, 7, 9)

odd_numbers[1] = 2 # Will give ERROR

# create a tuple called student while PACKING name, age, course and 
# phone number
# note: as you can see parantheses are optional while packing values 
# into tuple

student = 'John Doe', 27, 'Python v3', 1234567890
print (student)
# Output: ('John Doe', 27, 'Python v3', 1234567890)

# let's unpack the values from student tuple into individual variables
name, age, course, phone = student

print (name)
print (age)
print (course)
print (phone)

# Output: John Doe
# Output: 27
# Output: Python v3
# Output: 1234567890

student = 'John Doe', 27, 'Python v3', 1234567890

# let's unpack the values from student tuple into individual variables
name, age, course, phone = student

# get course from student tuple using indexing
print(student[2])
# Output: Python v3

# get course from student tuple using negative indexing, -1 is the last element
print(student[-2])
# Output: Python v3

# get course from student tuple using slicing
print(student[2:3])
# Output: ('Python v3’,)

# num_one of type integer
nun_one = 50
# num_two of type string
num_two_str = "150.75"
# num_two explicitly converted from string to number
num_two = float(num_two_str)