Lesson 01-08: User Input

Learning Target: I can write a program to get user input.

The best kinds of programs are often the interactive ones. Basic interactivity is easy to implement in python using the input function.

An important note: using the input function in the ActiveCode windows in the browser may have unintended side effects. For best results (and most accurate results), I highly advise you run this code in your own text-based python IDE.

The input() Function

The built-in input() function is a way to prompt the user to type something in. In python, this would be done in the console (where the output is). On this site, it will appear as a pop-up box. Inside the parentheses, you would put the prompt as a string. The prompt is what the user sees when you are asking for input. Run the following two examples as a demonstration.

 
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name = input("Hello, what's your name?")
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print("Hello " + name)
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​
 (ex_input1)



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prompt = "Hello, what's your name?"
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name = input(prompt)
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print("Hello " + name)
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​
 (ex_input2)


They should both do the exact same thing.  Notice how we put the input() function as part of a variable assignment statement.  This is because the input() function actually represents a value - the value being whatever was typed in to the prompt.






The Datatype of input()


An important question here is: what type of data does input() give you?  We can easily find out using the type() function.  Try running the example below.



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name = input("Hello, what's your name?")
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print(type(name))
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​
 (ex_input3)


So here, we’re asking the user Hello, what's your name? and saving their input in a variable called name.  We then print the datatype of name using the type() function.  The result is a string.  What if you had typed in a number?  Try running the example below.



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age = input("Hello, what's your age?")
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print(type(age))
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​
 (ex_input4)


Still a string!  We then know that The input function will always return a string, no matter what you type in.  This is important to know, because if we wanted to ask a user for a number, we would have to convert it using a conversion function before using.  See the following example:



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num = input("Enter a number and I will tell you 10 times that number: ")
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new_num = float(num) * 10
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print(new_num)
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​
 (ex_input5)






Checks for Understanding




Q#1


In the space below on line 2, write a statement that will ask the user to enter in their favorite food using input() and save it in a variable called fav_food.



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#
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​
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print("Your favorite food is " + fav_food)
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​
 (cfu_0108_1)






Q#2


In the space below on line 2, write a statement that will ask the user to guess a number between 1 and 10 using input(), convert it to an integer, and save it in a variable called guess.



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#
2
​
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print("You guessed: " + str(guess))
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​
 (cfu_0108_2)









  
      
  
  
  
  
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