الجلسة الثالثة من جلسات تعلم أساسيات لغة البرمجة بايثون

1. Conditions in python
‫إعداد‬:
‫م‬.‫محمد‬ ‫علي‬

2. Objective
 Inputs in python
 Ready functions in python
 Conditions in python
 If statement

3. Inputs in python
 First when we want to write a python program we must install a compiler
or must create a new python file and run it using the shell
 When we want to make user input from the keyboard we use the keyword
(input)
 Example: x=input()
 In this case the shell will wait us for input from keyboard
 We can show a message before input
 Example: y=input(‘input something’)
 Rule: every thing we input it from keyboard it
inputted as string

4. Ready functions in python
 After we input some thing from keyboard as string
 If we want to convert the input to another data type we must use some
ready function as:
 int(): to convert to int
 Example: int(x)…. Then x will be an int variable
 float(): to convert to float
 Example: float(y)…… then y will be a float variable
 str(): to convert to string
 Example: str(5)…. Then the 5 will be like ‘5’ as a string
 Rule: we can use this functions in print command

5. Conditions in python
 In python we have only (if statement)
 There is no switch….case statement
 If we want to implement (switch….case) statement we must create a new
function for this
 Rule: in python there is only if statement

6. If statement
 As all programming languages the if statement has the following syntax:
 if condition :
commands

7. If … else statement
 The syntax is:
 if condition:
command
 else:
command

8. If … elseif … else statement
 The syntax is:
 if condition:
command
 elif condition:
command
 else:
command

9. The biggest number
 x=5
 y=6
 z=10
 if x>y and x>z:
 print('the biggest number is: ',x)
 elif y>x and y>z:
 print('the biggest number is: ',y)
 else:
 print('the biggest number is: ',z)

10. The biggest number
 x=int(input('enter the first number: '))
 y=int(input('enter the second number: '))
 z=int(input('enter the third number: '))
 if x>y and x>z:
 print('the biggest number is x: ',x)
 elif y>x and y>z:
 print('the biggest number is y: ',y)
 else:
 print('the biggest number is z: ',z)