DEV Community: Isaac

Lothar Collatz hypothesis

Isaac — Sun, 02 Apr 2023 22:45:01 +0000

In 1937, a German mathematician named Lothar Collatz formulated an intriguing hypothesis (it still remains unproven) which can be described in the following way:

1.Take any non-negative and non-zero integer number and name it c0.
2.If it's even, evaluate a new c0 as c0 ÷ 2.
3.Otherwise, if it's odd, evaluate a new c0 as 3 × c0 + 1.
4.If c0 ≠ 1, skip to point 2.

The hypothesis says that regardless of the initial value of c0, it will always go to 1:

print("Prove that Lothar Collatz  is wrong!!!!")
c0 = int(input('Enter a non- negative, non-zero integer: '))
step = 0
while c0 != 1:
    if c0 % 2 == 0:
        c0 //= 2
        if c0 != 1:
            step += 1
            print(' New value is ', c0)
            continue
        elif c0 == 1:
            step += 1
            print(' New value is ', c0)
            break
    elif c0 % 2 == 1:
        c0 = c0 * 3 + 1
        if c0 != 1:
            step += 1
            print(' New value is ', c0)
            continue

print('Total Steps: ', step)
print("*"*44)
print("*"*44)

As you can see we have transform the whole Collatz idea in to a while loop that print every step needed to achieve the goal.
At the end we run a for loop with a sleep command to avoid the program to close abruptly after doing the calculations:

import time

for i in range(1,11):
    time.sleep(1)

print("*"*44)
print("*"*44)

Tax Calculator

Isaac — Sun, 02 Apr 2023 22:13:05 +0000

We are going to make a simple program to calculate two different taxes based on the user's income. We are going to call this tax PIB.
First we set the variable for the yearly income that is going to cut between the two taxes:

citincut=85528

Second we define our variables for the two different tax operations base on the user's input:

print("Best rewards loyal citizen, today its time to contribute your Personal Income Tax for the Kingdom of Thalia.")
citinput=float(input("Introduce Year Income:"))
citix=citinput-citincut

We set the logic operation for the two different taxes.
As you can see for the people with a lower income than 85528 we are going to apply a tax of the 18% of the income minus 556.2:

if (citinput<=citincut):
    tax=citinput*18/100-556.2
    print(round(tax),"Is your annual PIT, thank you loyal citizen.\n")

To avoid having a negative tax we introduce a if statement:

    if (tax<=0):
        print("Move Punk")

For the people with a higher income we are going to set a tax of 14839.2 plus 32% of the surplus over 85528:

elif (citinput>=citincut):
    tax=citinput-(14839.2+(citix*32/100))
    print(round(tax),"Is your annual PIT, Hail Thalia!\n")

You can change the value of the variable and use it for your own purposes.

Multi-Dimensional List

Isaac — Sun, 02 Apr 2023 21:03:34 +0000

we are going to create a multi-dimensional list to be able to store telephone numbers and user names together.

First we are going to create a function to run our menu within a loop:

def list():
    userlist=[["Jimmy",+34666777888],["Bobby",+34668669449],["Charlie",+341999101110]]
    while True:

        print ("*"*43)
        print ("\n*         Multi-Dimensional List         *\n")
        print ("*"*43)
        print ("\n*   1 - Display the users information    *\n")
        print ("*                                          *\n")
        print ("*   2 - Add a new user                     *\n")
        print ("*                                          *\n")
        print ("*   3 - Count the number of users          *\n")
        print ("*                                          *\n")
        print ("*   4 - Exit                               *\n")
        print ("*"*43)

As you can see we added some users already for testing purposes.
After setting the menu we are going to code the conditional statements for the different values of our user input:

        action = int(input("Please type the number to perform the action selected:\n"))

To display the elements without brackets:

        if action == 1:
              for i in range(len(userlist)) :
                for j in range(len(userlist[i])) :
                    print(userlist[i][j], end=" ")
                    print()
                continue

Adding new users:

        elif action == 2:
            print("Type new user name: ")
            newusername=input()
            print("Type new telephone number")
            newusertelephone=input()
            newuser="\n".join([newusername,newusertelephone])
            userlist.append([newuser])

For the next step we use len so we are going to count only the elements of the list that contains strings:

        elif action == 3:
            usercounter=len(userlist)
            print("Numbers of users:",usercounter)

To exit the program we break the loop:

        elif action == 4:
            break
        else:

            print("Invalid choice. Please try again.")
list()