Talk to the User
Getting the computer to stick your name on the end of "Hello " is nice, but why not just write "Hello [my name]"? Because you don’t have to know what’s going to be stored in a variable when you write the program. You can even ask the user of the program to tell you what to put into it.
Update your Python program so that it asks the user for the text to put in the variable:
name = input("What is your name?")
print("Hello "+name)
print("The Code, it's calling to you. Just let it in.")Try running it. You’ll need to press the Enter key once you’ve typed in your name.
Now, try collecting a number from your user by changing your code to look like this:
name = input("What is your name?")
my_number = input("Hello "+name+", please pick a number")
print("Your number is "+my_number)Notice that you can use the + on both sides of a variable!
Run this program, answer its questions, and watch what happens.
What if you want to add another number to the number stored in your new variable? Let’s try that.
Add a line to your program that will add 1 to the my_number variable:
name = input("What is your name?")
my_number = input("Hello "+name+" please pick a number")
my_number = int(my_number) + 1
print("Your number is "+str(my_number))How does the new code work?
You’ve just taken a value from a variable, changed it, and stored it back in the same variable — all on the same line!
Now, why does the code have int() and str() around my_number?
It’s because Python makes a difference between the number ‘1’ it uses for maths and the number ‘1’ it writes in a sentence. Putting int( ) around a variable tells it to treat it as an integer (a maths number), and putting str( ) around it tells it to treat it as a text string.
Integers and strings are variable types, and certain pieces of code (like + and print) only work if the variables you give them are the right type.
Maths in Python
You’ve seen how to add here, but you can also:
- Subtract using
- - Multiply using
* - Divide using
/