this is a readme file

I will be updating information on my python code here

#DICTIONARIES eg. dict = {'name': 'beau', 'color': 'blue'}

there is a key value pair, name = beau and color = blue

LIBRARIES:

import random = import random library practice F string

COMMANDS

isinstance type

#DATA TYPES complex for complex numbers int for integers float for floating numbers str for strings bool for booleans list for lists tuple for tuples range for ranges dict for dictionaries set for sets frozenset for frozensets

Arithmetic Operators: Used for performing mathematical calculations.

• (Addition)

• (Subtraction)

• (Multiplication) / (Division) % (Modulus - remainder of division) // (Floor division - quotient without remainder) ** (Exponentiation) Assignment Operators: Used to assign values to variables. = (Assign) += (Add and assign) -= (Subtract and assign) *= (Multiply and assign) /= (Divide and assign) %= (Modulus and assign) //= (Floor divide and assign) **= (Exponentiate and assign) := (Walrus operator - assign and return in an expression) Comparison Operators: Used to compare values. == (Equal to) != (Not equal to)

(Greater than) < (Less than) = (Greater than or equal to) <= (Less than or equal to) Logical Operators: Used to combine or modify boolean expressions. and (Returns True if both operands are true) or (Returns True if at least one operand is true) not (Returns the opposite of the operand's boolean value) Identity Operators: Used to check if two variables refer to the same object in memory. is (Returns True if both operands are the same object) is not (Returns True if both operands are not the same object) Membership Operators: Used to check if a value is present in a sequence (e.g., string, list, tuple). in (Returns True if the value is found in the sequence) not in (Returns True if the value is not found in the sequence) Bitwise Operators: Used to perform operations on individual bits of integers. & (AND) | (OR) ^ (XOR) ~ (NOT) << (Left shift)

(Right shift)

NOTE

escape double quote with back slash character "" - means escape

"\n" means new line

to escape a back slash, you have to escape back slashes too

All numbers are true except 0

A string will always be true unless it is empty

"+= command on will extend a list as an extend function will.

"any" command, is used to check if any value is true.

    check = any([1,0,0])

    print(check)

"all" command, is used to check if all values are true.

    check = all([1,0,0])

    print(check)

COMPLEX

    num1 = complex(2,3)

    print(num1.imag,num1.real)

Enums

    used to represent constants, recommend using upper case letters for members

Difference between a Dictionary and a SET

dictionaries have key value pairs example dict1 = {'emmanuel':1, 'izu':2, 'nkwocha':3}

while a set has no key value pair example set1 = {'emmanuel','izu','nkwocha'}

THE NONLOCAL COMMAND

The non local is used to call a variable in a nexted function.

def do(): num1 = 0

def incr():
    nonlocal num1
    num1+=1
    return num1

return incr()

print(do())

OBJECTS

An object is an instance of a class

SPLIT METHOD

full_name = "Emmanuel Izuchukwu Nkwocha"

splitname = full_name.split()

print(splitname[1])

DOC STRING

written using three double quote, example below is a class with DOC string, called using the help function.

class User: """This is a user class for this program, please refer to the help file for more class description"""

def __init__(self):
    self.first_name = 'Emmanuel'
    self.last_name ='Nkwocha'

user1 = User() print(user1.first_name) print(user1.last_name)

help(User)

Example class calling fields from an Enum class

from enum import Enum

class hold (Enum): emmanuel = 1 Nkwocha = 2

class User: """This is a user class for this program, please refer to the help file for more class description"""

def __init__(self):
    self.first_name = 'Emmanuel'
    self.last_name ='Nkwocha'
    self.number = hold.emmanuel.value

user1 = User() print(user1.first_name) print(user1.last_name) print(user1.number)

Inheritance.

The User class is inheriting from the education class

class education: def edu(self): return "I have a masters degree"

class User(education): """This is a user class for this program, please refer to the help file for more class description"""

def __init__(self):
    self.first_name = 'Emmanuel'
    self.last_name ='Nkwocha'

user1 = User() description = f"My name is {user1.first_name} {user1.last_name}, and {user1.edu()}"

print(description)

Modules

if name == "main": this ensures a particular script is called only when run locally.

Importing a module from a LIB.

first you need to create the init.py file in the library before that can work.

STANDARD LIBRARY

example math and json

Lambda Functions.

    lambda argurments: expression
    # map
    The map() function in Python is used to apply a given function to each item of an iterable (like a list, tuple, or set) and returns an iterator that yields the results. It provides a concise way to perform operations on sequences without using explicit loops. The map() function takes two arguments: the function to apply and the iterable to process. 

def square(x): return x * x

numbers = [1, 2, 3, 4, 5] squared_numbers = map(square, numbers)

print(list(squared_numbers))

Expected output: [1, 4, 9, 16, 25]

below is same code solved with lambda

lst1=[1,2,3,4,5]

double_them = list(map(lambda x : x * x, lst1))

print(double_them)

    # filter 
    he filter() function in Python is used to construct an iterator from elements of an iterable for which a function returns true. It essentially filters a sequence based on a given condition. The filter() function takes two arguments: a function and an iterable. The function is applied to each item in the iterable, and if the function returns True, the item is included in the resulting iterator. If the function returns False, the item is excluded. 

def is_even(x): return x % 2 == 0

numbers = [1, 2, 3, 4, 5, 6] even_numbers = filter(is_even, numbers) print(list(even_numbers))

Expected output: [2, 4, 6]

below is same code with lambda

lst1=[1,2,3,4,5,6]

filter_them = list(filter(lambda x : x % 2 == 0, lst1))

print(filter_them)

RECURSION

class inheritance.

class education:
def edu(self):
    return "I have a masters degree"

class User(education): """This is a user class for this program, please
refer to the help file for more class description"""

def __init__(self,f_name,l_name):
    self.first_name = f_name
    self.last_name = l_name
    

def doit(self):
    print(self.first_name)
    print(self.last_name)
    edu = self.edu()
    print(edu)

def bark(): print("woof!")

if name == "main":

user1 = User('Emmanuel','Nkwocha')
user1.doit()

Decorators

def my_decor(func): """This is a decorator """ def add_func(): print("Do this first") func() print("Do this later") return add_func

@my_decor def say_hello(): print("hello here")

@my_decor def say_Hi(): print("Hi here")

say_hello() say_Hi()

Annotations

def add (a : int, b : int) -> float: return float(a+b)

print(add(3,3))

Exception

try: a : int = input('Enter your second value') b : int = input('Enter your first value') addition = int(a + b) except ZeroDivisionError: print('You cannot divide by zero')

except ValueError: print('this operand is not supported')

else : print(f"the answer is {addition}")

finally: print('good job, well done')

WITH COMMAND

LIST COMPRESSIONS

numbers = [1,2,3,4,5] numbers_power_2 = [n**2 for n in numbers]

print(numbers_power_2)

POLYMORPHISM

You could use the if statement to check if a list is empty

Example Dictionary

dict1 = { "firstname" : "Emmanuel", "Middlename" : "Izuchukwu", "lastname" : "Nkwocha" } print(dict1.items())

for key,value in dict1.items(): print(key , value)

sorted() - used to sort a list or dictionary.+

Abritrary Number of Arguments

def call_names(*names): print(names)

call_names('emmanuel','izu','nkwocha')