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Python Sheet

Counting Down

while True:
    user_number = input ("Enter a number")

    number = int (user_number)

    countdown_string = ""

    while number > 0:
        countdown_string = countdown_string + str(number)
        number = number - 1
        
    print (countdown_string)

Area of Triangle

#write a function
#name: areaofTriangle
#parameter: base height
#return: area
def areaofTriangle (base, height):
    return 1/2baseheight

user_base= float(input("Enter the base of the triangle: "))

user_height= float(input("Enter the height of the triangle: "))

#function call
print ("The area of the triangle is", areaofTriangle (user_base, user_height))

Returning largest value

#write a function that returns the largest of two values
# name: max2
# arguments: num1, num2
#return: the largest value

def max2 (num1, num2):
    maxvalue = num1
    if num2 > maxvalue:
     maxvalue = num2
    return maxvalue

print (max2 (2,3))
print (max2 (2,99))
print (max2 (2,55))

#write a function that returns the largest of three values
# name: max3
# arguments: num1, num2, num3
#return: the largest value

Vocabulary

Variables
a value that can change, depending on conditions or on inform­ation passed to the program.
String
list of charac­ters, symbols and could also have numbers.
Syntax
structure of a program.
Print
to display a value on the screen
Loop
when the instru­ctions repeat over and over.
Integer Number
Whole number/ counting number
Float Number
The number in decimal
Modulo
Used to finds the remainder
Boolean
True/False
List
Writing consec­utive words, numbers down, one below the other in []
Algorithm
A list of steps to finish something. Instru­ctions that can be performed with or without a computer.
Code
Commands created to allow computer to perform the functions.

Addition

string + string
Combines that strings together (squished together)
string + number
Crash!
number + number
Addition (Math)

Random List

import random

intlist = [1,2,3,4,5]
random_int = random.choice(intlist)
print (intlist, random_int)

fplist = [1.0,2.0,3.0,4.0,5.0]
random_fp = random.choice (fplist)
print (fplist, random_fp)

strlist = ["candy", "marshmellow", "icecream", "lollipop"]
random_str = random.choice (strlist)
print (strlist, random_str)

mylist =[1,2,3, 5.0,6.0,7.0, "Candy", "Icecream", "Gummybears"]
random_item = random.choice (mylist)
print (mylist, random_item)
myvar1 = 1
myvar2 = 2
myvar3 = 3
varlist = [myvar1, myvar2, myvar3]
random_var = random.choice (varlist)
print (varlist, random_var)
 

Countdown Machine

user_number = input("What number do you want to count down?")
number = int(user_number)
countdown_string = ' '

while number > 0:
countdown_number =countdown_string + str(number) + " "
number = number -1
#print(number)

print (countdown_string)

Receives number from user. State if Neg,Po­s,Zero

while True:
    user_input = input ("Enter a number: ")
    user_input = int(user_input)
    if user_input > 0:
        print (user_input, "is positive.")
    elif user_input < 0:
        print (user_input, "is negative.")
    elif user_input == 0:
        print (user_input, "is zero.")

Area of Circle

def areaOfCircle (r): #r=radius
    pi = 3.1415
    area = pi r *2
    return area
user_radius = input ("Enter the radius:")
radius = float(user_radius)
print ("The area of the circle is", areaOfCircle(radius))

mylist, print all item using loop

mylist = [1,2,3]
for item in mylist:
    print (item)

F


def myprint (text): #text is (something your giving to the function) an argument (parameter) to the function
    print ("" + str(text) + "")
    return #This exits the function

myprint(1)
myprint(2.5)
myprint ("hello")

def myprint2 (text, decoration):
    print (decoration + text + decoration)
    return

myprint2 ("hello", "+++")
myprint2 ("hello", "_=_=_=")
myprint2 ("hello", ">>>>>>")

def double (number):
    return number * 2 #return value

print(double(2))
myvar = double(double(3)) #same as double (6) because double(3) == 6
print(myvar)

Ask input from user

user_input = input("Enter a number:")
user_input = int (user_input)
print (user_input*5)

Output

x = false
print (x and True or 1 ==1)

#OUTPUT = TRUE

returning largest value continue

def max3 (num1, num2, num3):
    maxvalue = num1
    
    if maxvalue < num2:
        maxvalue = num2
    if maxvalue < num3:
        maxvalue = num3
    return maxvalue
print (max3 (8,4,3))

#write a function that returns the largest number in the list
#name : maxlist
#argument: list
#return: the largest value in the list

Function

float()
Change number to be decimal number.
print()
Show inform­ation that you want on the screen.
int()
Change the number­/string into a integer.
str()
A list of number, letter and symbols.
input()
Gain inform­ation from user.
len()
The length of the string

Multip­lic­ation and Exponents

string * number
Combines that string in the amount of numbers.
string *string
Crash!
number * number
Multiple (Math)
string **string
Crash!
number ** number
Exponent (Math)
string ** number
Crash!
 

Print all even numbers from -100 to -1. While loop

mynum = -100
while mynum <-1:
    print (mynum)
    mynum= mynum + 2

Function

#how to create a function 1
def NameofFunction (myvar1, myvar2):
    print ("hello")
    return myvar1, myvar2
#function call
NameofFunction (2, 3)
#Code above, prints only hello

#2

def NameofFunction (myvar1, myvar2):
    print ("hello")
    return myvar1 + myvar2

#function call
NameofFunction (2, 3)
myanswer = NameofFunction (4,1)
print (myanswer)
#code 2 prints out hello hello and 5

Operations

def sum(a,b):
    return a + b
def product (a,b):
    return a * b
def diff (a,b):
    return a - b
def div (a,b):
    if b != 0:
        return a // b
    else:
        print ("Error")

def calc(num1, num2, operation):

    if operation == "sum":
        return sum (num1, num2)
    elif operation == "product":
        return product (num1, num2)
    elif operation == "diff":
        return diff (num1, num2)
    elif operation == "div":
        return div (num1,num2)
    
print (calc(1,2, "sum"))
print (calc(4,2, "diff"))
print (calc(10,0, "div"))
print (calc(2,12, "product"))

Volume Of Prism

#Write the function compute volume of prism
#name: volumerOfPrism
#Parameter: base, height, prism_height
#return volume

def volumeOfPrism (base, height, prism_height):
    #area * prism_height
    volume = areaOfTriangle (base,height)* prism_height
    return volume

user_prism_height = float(input("Enter the prism height: "))
print ("The volume of the prism is", volumeOfPrism (user_base, user_height, user_prism_height))

returning largest value continue2

def maxlist (list):
    maxvalue =(list[0])
    for item in list:
        if maxvalue < item:
            maxvalue = item
    return maxvalue
print (maxlist(range(0,123)))

Naming Convention

Rules for giving names
- letters
- numbers (Can't be the first letter)
- underscore _

Valid
- _mystr
- my3
- Hello_there

Invalid name
- 3my="hi" -- cannot start with number
-firstname ="hi"
= first-name

Examples

print (2) - integer
print (2.5) - floating point
print ("Hello") - string
print (mystr) - variable
print (mystr, "hi", 2,1,0) - - commas

mystr = "Hi"
mystr - name
"Hi" - value can change
print (int(1.5)) - 1
print (int ("2") - 2
print (float (1)) - 1.0 anything to a float

Reverse Word

while True:
    word = input("Please enter a word: ")
    index = 0
    reverse = ''

    while index < len(word):
        reverse = word[index] + reverse
        index = index + 1

        print ("Reverse ", reverse)

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