Python Programming Tutorials

# A Variable thats stores the word hello
a  = "hello"

# To Show or Output the variable
print(a)

# Check for the datatype
type(a)

# Variables can store different datype
num = 2

type(num)

# it can be a boolean
t = True
type(t)

# Behind the scene using disassembly
import dis

dis.dis(a)

# Disassembles a code object indicating last instruction
dis.disco(a)

# Numbers
print("Addition: 2 + 4 = ",2 + 4)
print("Subtraction: 4 - 2 = ",4 - 2)
print("Division: 9 / 2  =",9 / 2)
print("Multiplication: 2 * 4 = ",2 * 4)
print("Modulus: 20%3  =",20%3)
print("Exponent: 4 **2 = ",4 **2)
print("Floor Division(remove digits after dec.pts): 9 // 2 = ",9 // 2)

x = 10
print("+ `+=` add AND ,x += 1 == x = x + 1",x += 2)
print("+ `-=` subtract AND,(x -= 1 == x = x - 1)",x -= 2)
print("+ `*=` multiply AND,(x *= 1 == x = x * 1)",x *= 2)
print("+ `/=` divide AND,(x /= 1 == x = x / 1)",x /= 2)
print("+ `**=` exponent AND,(x **= 1 == x = x ** 1),",x **= 2)

name = "hello python"

type(name)

# List All Attributes and Methods
dir(name)

# Convert 
print("Uppercase:",name.upper())
print("Lowercase:",name.lower())
print("Titlecase:",name.title())
print("Capitalize:",name.capitalize())
print("Swapcase:",name.swapcase())

# Find the length of string
len(name)

# String Indexing or Splicing
# Starts from 0 not 1
name[0]

name[0:5]

# From begining to end
name[0:]

# Reverse
name[::-1]

# Find the position of the character
name.find('l')

# Find the number/count of a character
"remember".count('e')

# Check if a character is in a string
'e' in "remember"

# Find the Position or Index of a character
"remember".index('e')

# Find the starting index position Index of a character
"remember".find('e')

# Check if a string has digits or alphabet
"remember".isalpha()

# Check if a string has digits or alphabet
"remember".isdigit()

# Check if a string has digits or alphabet
"remember23".isalnum()

# Startswith
"alpha".startswith("a")

# endswith
"alpha".endswith("a")

# Replace and Split
"hello python".replace("python","julia")

# Replace and Split
"hello python".split()

# String Concatenation
greet = "hello"
fname = "John"

# Method 1
greet + fname

# Method 2
"{} {}".format(greet,fname)

# Method 2
"{0} {1}. Yeah {0}".format(greet,fname)

# Method 3 Using F-Strings
f"{greet} {fname}"

# Method 4 Using F-Strings
F"{greet} {fname.upper()}"

### Extra
import string

dir(string)

# Get All the Alphabets
string.ascii_letters

# Get All the Digits
string.digits

# Get All Punctuations and Special Characters
string.punctuation

# Creating a List of different datatypes
arr = [1,3,"bonjour","medaase",3.5]

# Check for the type
type(arr)

arr2 = list((2,4,5.6,"holla"))

arr2

type(arr2)

# Methods and Attributes of a List
dir(arr)

# Check for the length of a list
len(arr)

# Slicing/Indexing
arr[0:5]

# From 3 till the end
arr[3:]

# Last 2 values
arr[-2:]

# Adding to the list element at one location
arr.append(arr2)

print(arr)

# Delete the last value
arr.pop()

arr

# To Extend the list
# Adds element one by one in distinct locations
arr.extend([10,20,30])

arr

#### Note The Difference Between Extend and Append
even = [2,4,6]
odd = [3,5,7]
even.extend([8,10,12])
odd.append([8,10,12])

print("Extending::",even)
print("Appending::",odd)

# Sorting A List
fruits = ["mango","apple","nut","banana"]

# Apply the sort function to the list
fruits.sort()

fruits

# Reverse sort
fruits.sort(reverse=True)

fruits

# Inserting An Element into a List
companies = ["Facebook","Netflix","Google","Apple","Amazon"]

# Insert JCharisTech into the 2 position List
companies.insert(2,"JCharisTech")

companies

import array

dir(array)

# Arrays of Integer
custom_arr = array.array('i',[1,2,3])

custom_arr

# Check Type
type(custom_arr)

# Extra
import numpy as np

# Create Arrays of Different dimensions
arr_0dim = np.array(42)
arr_1dim = np.array([1, 2, 3, 4, 5])
arr_2dim = np.array([[1, 2, 3], [4, 5, 6]])
arr_3dim = np.array([[[1, 2, 3], [4, 5, 6]], [[1, 2, 3], [4, 5, 6]]])

# Check for Dimensions and size
print("Dimensions:",arr_0dim.ndim, "Size",arr_0dim.size)
print("Dimensions:",arr_1dim.ndim, "Size",arr_1dim.size)
print("Dimensions:",arr_2dim.ndim, "Size",arr_2dim.size)
print("Dimensions:",arr_3dim.ndim, "Size",arr_3dim.size)

# Check the type
type(arr_0dim)

# Create A List/Array of Zeros or Ones
ones = np.ones(20)

ones

# Create A Dictionary
# Method 1
students = {'name':'Mark','age':23,'address':'London'}

# Create A Dictionary
# Method 2
students2 = dict({'name':'John','age':20,'address':'Accra'})

# Check type
type(students)

# Check type
type(students2)

# Methods or Attributes
dir(students)

# Get All the Keys in the dictionary
students.keys()

# Get All the values in the dictionary
students.values()

# Get All items in the dictionary
students.items()

# Find a Value using bracket notation or index
students['name']

# Find a Value using get function
# Best method if you don't know the key
students.get('name')

### When to use [] and get()
students['names']

# Find a Value using get function
# Best method if you don't know the key
students.get('names')

# Iterating 
for k,v in students.items():
    print('{} ==> {}'.format(k,v))

parents = {'job':'Doctor','nationality':'Ghana'}

# Updating Dictionary
students.update(parents)

# Deleting or Removing the last
students.popitem()

students

students

# Python Trick For Merging Dictionary
# Method 1
family = {**students,**parents}

family

# Method 2
family2 = dict(students2,**parents)

family2

# Creating a Tuple
t1 = (2,3,4,5)

# Check type
type(t1)

# Methods and Attributes
dir(t1)

# Length 
len(t1)

# Indexing
t1[0:2]

# Are Immutable(You can't change them)
t1[2] = 40

### Extra
from collections import namedtuple

# Declaring namedtuple() 
Student = namedtuple('Student',['name','age','DOB'])

Student

# Check Type
type(Student)

# Adding values 
S = Student('Paul','19','2541997')

S

# Access using index 
print ("The Student age using index is : ",end ="") 
print (S[1])

# Access using name  
print ("The Student name using keyname is : ",end ="") 
print (S.name)

# Access using getattr() 
print ("The Student DOB using getattr() is : ",end ="") 
print (getattr(S,'DOB'))

# Method 1
all_nums = {0,1,2,3,4,5,6,7,8,9}
even_nums = {2,4,6,8}

# Method 2
prime_num = set([2,3,5,7,11])

#Check they type
type(all_nums)

type(prime_num)

# Methods and Attributes
dir(all_nums)

# Adding to A Set
prime_num.add(13)

prime_num

# Removing an item (remove or discard)
prime_num.remove(2)

prime_num

# using discard() : doesn't raise an error if not found
prime_num.discard(2)

prime_num

# Raises a Key Error if you use remove()
prime_num.remove(2)

# Remove the last item with pop
# Since they are unordered it can pop out any number 
prime_num.pop()

prime_num

# Remove all element with clear()
prime_num.clear()

prime_num

odd_nums = {1,3,5,7,9}

# Union of Sets
# Method 1: Doesnt change the sets
even_nums.union(odd_nums)

even_nums

even2 = even_nums

# Union of Sets by updating
# Method 2: Does change the initial sets
even2.update(odd_nums)

even2

even_nums

# Intersection of Sets
even_nums.intersection(odd_nums)

# Subset
even_nums.issubset(all_nums)

# Difference of Sets
even_nums.difference(odd_nums)

# isdisjoint of Sets
even_nums.isdisjoint(odd_nums)

import matplotlib_venn

dir(matplotlib_venn)

from matplotlib_venn import venn2,venn3,venn2_circles
import matplotlib.pyplot as plt

# Plot 2 Venn diagrams
venn2([even_nums,odd_nums],('Even Numbers','Odd Numbers'))
plt.show()

# Plot 2 Venn diagrams
venn2([all_nums,odd_nums],set_labels=('All Numbers','Odd Numbers'))
plt.show()

x = 30
y = 20

# if and else
if x == 30:
    print("X is equal to 30")
else:
    print("X is not equal")

# if ,elif and else
if x == 30:
    print("X is equal to 30")
elif x < 20:
    print("X is less")
else:
    print("X is not equal")

print("Equal") if y == 20 else print("Not Equal")

languages = ["Javascript","Python","C","C++","Julia","Golang","Assembly"]

# looping through our sequence
for i in languages:
    print(i)

# Looping through a string
for s in "hello world":
    print(s.upper())

# Using the Break Statement
# use to stop the loop before it iterate through all items
for lang in languages:
    print(lang)
    if lang == 'Python':
        break

# Using the Continue Statement
# use to continue the loop 
for lang in languages:
    if lang == 'Python':
        continue
    print(lang)

# Using the Pass Statement
# for loops cannot be empty hence we use pass  to pass the loop  without erros
for lang in languages:
    pass

# End
range(10)

# Start to End
range(0,20)

# Start to End with Step
range(0,20,2)

# Looping through
for i in range(10):
    print(i)

# Looping through
for i in range(0,10,3):
    print(i)

# Print i as long as i is less than 6
i = 1
while i < 7:
    print(i)
    i = i + 1
    # i+=1

# Defining a function
def my_function(name):
    print("Hello ", name)

# Calling a function
my_function("Jesse")

# Check the type
type(my_function)

# You Can Assign a function to a variable
new_func = my_function

new_func("John")

import dis

# methods/Attributes of dis
dir(dis)

dis.dis(my_function)

# Check for the code
my_function.__code__

# Check for the bytecode
my_function.__code__.co_code

# Check for the name of the function
my_function.__code__.co_name

# Check for stacksize
my_function.__code__.co_stacksize

# Check for the non local variables
# Global variables
my_function.__code__.co_names

# Check for the local variables
my_function.__code__.co_varnames

# Defining a function with a return statement
def my_function2(name):
    result = "Hi {}".format(name)
    return result

my_function2("Jane")

dis.dis(my_function2)

def buy_items(*items):
    items_list = [*items]
    return items_list

buy_items("Banana")

buy_items("Banana","Apple","books")

# Simple function with a keyword argument and a defaul parameter value of 0
def triangle(base=0,height=0):
    result = 1/2*base*height
    return result

# In a positional way
triangle(20,40)

# In a keyword way ireespective of position
triangle(height=40,base=20)

### Working with **kwargs
def make_emails(**names):
    emails = "@".join(names.values())
    return emails

make_emails(fname="Jesse",lname="Agbemabiase")

make_emails(fname="Jesse",lname="Agbemabiase",email="gmail")

dis.dis(make_emails)

def do_task(name):
    """Do this task """
    print("Doing ",task)

# To get the docs
# method 1 using help
help(do_task)

#  To get the docs using __doc__
do_task.__doc__

# Inside Jupyter or Ipython
?do_task

print("Hello Learner")

age = input("Enter Your Age")
print(age)

# Open A File and Create A File By Writing o it
file1 = open("examplefile.txt","wb")

file1.write(b"Writing to textfile")

file1.close()

# Open A File and Create A File By Writing o it
with open("examplefile.txt","rb") as f:
    data = f.read()
    print(data)