Vocabulary
Variable |
Hold a value and can be change |
String |
A list of character such as number, better and symbols |
Integer number |
Whole number/ counting number |
Float number |
The umber in decimal |
Syntax |
Grammar/Structure of language |
Modulo |
Find the remainder |
Boolean |
True/False |
Addition
string+string |
combines the strings together |
string+number |
crash |
number+number |
math(addition) |
Multiplication and Exponents
string* string |
crash |
string* number |
combines the string multiple times |
number* number |
math(multiply) |
string** number |
crash |
number** number |
exponent(math) |
string** string |
crash |
Example
mylist3 = [1, 'hello', 2.3]
print (mylist)
print (mylist2)
print (mylist3)
#how to make a list with all number from 0-99
mynumbers = range(5)
for num in my numbers:
print (num)
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Example: Create function
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)
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")
print (calc(10, 0, "div"))
print (calc(1,2,"sum"))
print (calc(4,2,"diff"))
print (calc(9,3,"div"))
print (calc(2,12,"product"))
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Maximum
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(3,4))
# write a function that returns the largest of three values
# name: max3
# arguments: num1, num2, num3
# return: the largest value
def max3 (num1,num2,num3):
maxvalue = num1
if num2 > maxvalue:
maxvalue = num2
if num3 > maxvalue:
maxvalue = num3
return maxvalue
print (max3(3,4,8))
# write a function that returns the largest number in a list
# name: maxlist
# argument: list
# returns the largest value in the list
def maxlist (list):
maxvalue = list[0]
for item in list:
if item > maxvalue:
maxvalue = item
return maxvalue
list = [1,2,3,6,19,50,2,4,5]
print (maxlist(list))
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Range()
#creates a list of numbers from 0 to the specified
number
numberlist = range(5)
# is the same as creating the following list
numberlist2 = [0, 1, 2, 3, 4]
for num in range(100):
print (num) # prints all numbers from 0 – 99
for num in range(5, 50):
print(num) #prints all numbers from 5 - 49
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From Worksheet
Write a program that repeatedly receives positive integers from the user. When the user enters a negative integer, exit the loop an print how many of the number entered were odd and even.
evencount = 0
oddcount = 0
while True:
user_input = int(input("Enter the number: "))
if user_number < 0:
print("Even: ",evencount)
print("Odd: ",oddcount)
break
elif user_input > 0:
if user_input % 2 ==0:#even
evencount = evencount + 1
else:
oddcount = oddcount + 1
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Even number from -100 to -1(While loop)
num = 0
while num > -100
number = num -2
print (num)
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From worksheet
Determines that number is negative, positive or zero
Ex; 4 is positive / 0 is Zero / -8 is negative
user_num = input ("Enter the number")
user_num = int(user_num)
If user_num == 0
print (user_num,"iszero")
elif user_num < 0:
print (user_num," is negative")
elif user_num > 0:
print( user_num, "is positive")
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Write a function(multiplication table)
def multipicationTable():
user_input = int(input("Enter a number: ")
num = 1
while num <= 10 :
print (user_input, "", "num", "=", "user_inputnum")
num = num + 1
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Functions
print() |
Show information that you want on the screen |
input() |
Gain info from the user |
int() |
Change number to be number integer |
float() |
Change number to be decimal number |
str() |
All ;ist of number, letter and symbols |
len() |
The length of the string |
# |
Comment, no effect |
Math
== |
equal to |
!= |
no equal to |
< |
less than |
> |
more than |
<= |
less than or equal to |
>= |
more than or equal to |
% |
Modulo, Find the remainder |
Reverse Word
while True:
word = input("Please enter word")
index = 0
reverse = ' '
while int(index)<len(word)
reverse = word[index] + (reverse)
index = int(index) + 1
print("Reverse:", reverse)
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Import random
import random
intlist = [1,2,3,4,5]
random_int = random.choice(intlist)
print (intlist, random_int)
fplist = [1.5,2.5,3.5,4.5,5.5]
random_fp = random.choice(fplist)
print (fplist, random_fp)
strlist = ['1', '2', '3', '4', '5']
random_str = random.choice(strlist)
print (strlist, random_str)
mylist = [1, 2, 3, 4, 5, 1.5, 2.5, 3.5, 4.5, 5.5, '1', '2', '3', '4', '5']
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)
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Function call
def printDefinitions (word):
if word == "variable":
# variable
print ("""
a variable is are nothing but reserved memory locations to store values or something that can be change.
""")
elif word == "function":
# function
print ("""
a function is the thing that define and put the code in there to reuse it again.
""")
elif word == "function call":
#function call
print ("""
a function call is function that already have code and can use it.
""")
elif word == "parameter":
#parameter
print ("""
a parameter is something that we put in function to define variable
""")
elif word == "argument":
#argument
print ("""
a argument is the parameter.
""")
elif word == "string":
#string
print ("""
a string is a letter.
""")
else:
print ("Unknown word")
while True:
user_input = input("Enter a word to define: ")
printDefinitions(user_input) # function call
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Forever While Loop
while True: # forever
user_input = input('Enter a number: ')
number = int(user_input)
print ('The number squared is', number ** 2)
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Decision Making/Conditional Statements:
if 3 < 2: #if statement must compare two Booleans
print ('3 is less than 2')
elif 4 < 2: #can have 0 or more elif statements
print ('4 is less than 2')
elif 5 < 2:
print ('5 is less than 2')
else: #can have 0 or 1 else statement at the end
print ('none of the above are True')
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Lists:
mylist = [2,3,4,5] # create a list
#select an item from a list
print (mylist[0]) #selects first item and displays 2
# len() determines the length of the list
print (len(mylist)) # displays 4
mylist.append(5) # adds an item to the end of the list
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Exercise
'''1. Write a program that uses a for loop to print out all the items from a list
called theList'''
theList = [1,2,3,4]
for item in theList:
print(item)
'''2. Write a program that uses a while loop to print out all the items from a list
called whileList'''
whileList=['bacon', 'cokezero', 'pepsi']
num = 0
while num < len(whileList):
print(whileList[num])
num = num + 1
'''3. Write a program that repeatedly accepts user input, prints out the length of
whatever they type in and quits when the user enters the word 'exit' '''
while True:
user_input = input('Enter a word: ')
if user_input == 'exit':
break
else:
print (len(user_input))
'''4. Create a function called theFunction, that has no parameters
and returns nothing. This function should repeatedly accept user input until
the user enters the word 'stop'. Call this function and run it.'''
def theFunction():
while True:
user_input = input('Enter a word: ')
if user_input == 'stop':
break
return
#call the function(function call)
theFunction()
'''5. Create a function called computeThis, that takes two parameters, a1 and b2.
The function should return the product of both parameters. Call this function
and print the result.'''
def computeThis(a1, b2):
return a1 * b2
print ("Product of 2 and 3 = ",computeThis(2,3))
'''6. Create a function called finalFunction, that has 1 argument called string.
The function should print the argument surrounded by "**" and return nothing.
Call this function. '''
def finalFunction(string):
print ('*' + string + '*')
finalFunction('hello')
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Naming Convention
Rule for giving name
- letter
- numbers
- underscore_
Valid name
- _myStr
- my3
- Hello_there
Invalid name
- 3my="hi" --cannot start with number
- first name="hi'
- first-name
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Convert to binary
user_number = ' '
while user_number != ' 0 ' :
user_number = input("Enter a number to convert to binary")
number = int(user_number)
binary_string = ' '
while(number > 0):
remainder = number%2
binary_string = str(remainder)+ binary_string
number = number/ /2
print("Binary string is", binary_string)
number = number/ / 2
print("Binary string is", binary_string)
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Countdown Machine
user_number = input(:What number do you want to countdown?")
number = int(user_number)
countdown_string = ' '
while number > 0:
countdown_number = countdown_string + str(number) + " "
number = number - 1
#print(number)
print (countdown_string)
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Example
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
mtstr (int(int)) ➤ 1
print (int("2")) ➤ 2
print (float(1)) ➤ 1.0 anything to a float |
Example
def myprint(text) : #mtvar is an argument (parameter) to he function
print ("" + str(text) + "")
return #return exists the function
myprint(1)
myprint(2.5)
myprint("hello")
def myprintnew(text, decoration) : #text and decoration are arguments to the function
print (decoration + text + decoration)
return
myprintnew("hello", "+++")
myprintnew("hello", "-=-=-=-=-=")
myprintnew("hello", ">>>>>>")
def doubleIt(number) :
return number * 2 #return value
print (timesTwo(2))
myvar + timesTwo(timesTwo(3)) #same as timesTwo(6) bacuse timesTwo(3) == 6
print (myvar) # it will display 12
def areaOfCircle(r):
if r <= 0:
return "Error: invalid radius"
pi = 3.1415
area = pi r * 2
return area
user_radius = float(input("Enter the radius: ")
print("The area of the circle is", areaOfCircle(user_radius))
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Conditional While Loop
count = 0 # start at zero
while count < 10: # loop while count is less than 10
print(count) #will print numbers 0 - 9
count = count + 1 #must increase count
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Printing values:
print("hello", "there") #displays hello there
print("hello" + "there") #displays hellothere
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For‐Loop with List:
forlist = [3, 4, 5, 2, 1]
for item in forlist:
print(item)
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While Loop with List:
thelist = [4, 3, 2, 1, 0]
index = 0 # start at the first item
while index < len(thelist):
print (thelist[index]) #prints each item
index = index + 1
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Comments
# hashtag – everything after # is a comment not code
"""
Double quote - Multi-line comment, everything in
between three double quotes is a comments
"""
''' Single quote - Multi-line comment, everything in
between three single quotes is a comments '''
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From worksheet
0
01
012
0123
01234
mystring = " "
count = 0
while count < 5:
mystring = mystring + str(count0
print (mystring)
count = count + 1
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From worksheet
Use a for loop to print the following:
0
012
0123
01234
mystring = ""
for num in range(5)
mystring = mystring + str(num)
print (mystring)
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From worksheet
Create a program to receive a number from the user and determine if that number is divisible by3.
Example:
- 9 is divisible by 3.
- 7 is not divisible by 3.
user_num = int(input("Enter the number: "))
if user_num%3 == 0:
print(user_num, "is divisible by 3")
else:
print(user_num, " is not divisible by 3")
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Print all items in the list
Give a list called mylist, print all items in the list using a loop.
mylist = [1,2,3,4]
for item in mylist:
print (mylist)
Another method
num = 0
while num < len(mylist)
print(mylist[num])
num = num + 1
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Created By
Metadata
Favourited By
Comments
memfail, 04:48 4 Jan 19
Hi Warisara, nice work. Please fix title - Python is spelled incorrectly. Thanks.
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