Stretch tasks Input and data types

Round 1: Quiz Blitz

1. Text, a string input always gives text, even if the user types a number.
2. A TypeError: you cannot add 1 to text input gives the text "7", and Python cannot add the number 1 to text.
3. age = int(input("Age? ")) int() converts the text from input into a whole number.
4. float A float holds numbers with decimals.
5. bool True and False are Boolean values, type bool.
6. 34 Both are text, so + joins them together.
7. You scored 15 str turns 15 into the text "15", which can be joined to the other text.
8. False "7" is text, a string. 7 is a number, an int.
9. print("You scored", score); print("You scored " + str(score)) Use a comma, or convert the number with str() before joining it with +.
10. 8 int turns the text "7" into the number 7, and 7 + 1 = 8.
11. name = input("Name? ") → greeting = "Hello " + name → print(greeting) Get the input, build the message, then print it.
12. ValueError hello cannot be turned into a whole number, so Python raises a ValueError.

Round 2: Quick Fire

1. • input always gives text, a string
   • You cannot add a number to text
   Model answer

   input always gives text, a string, even if the user types a number. You cannot add the number 1 to text, so Python gives a TypeError.

2. • Convert it with int()
   • Put int() around the input
   Model answer

   Convert it with int(), wrapped around the input: age = int(input("Age? ")). This turns the text into a whole number.

3. • int, such as 7
   • float, such as 3.14
   • str, such as "hello"
   • bool, True or False
   Model answer

   int, such as 7. float, such as 3.14. str, such as "hello".

4. • "7" is text, a string
   • 7 is a number that you can do maths with
   Model answer

   "7" is text, a string, so it cannot be added up. 7 is a number, an int, so you can do maths with it.

Round 3: Big Think

1. • Use a comma inside print
   • Convert the number with str() and then join with +
   • + joins pieces of text together
   • + cannot join text and a number, so it gives a TypeError
   • With a comma, Python handles the types for you
   Model answer

   The first way is a comma: print("You scored", score), which Python handles for you, adding a space. The second way is to convert the number to text with str() and join them with +. "You scored " + score fails because + cannot join text and a number, so Python gives a TypeError.

2. • input gives a string even when the user types a number
   • Adding a number to it gives a TypeError
   • An example, such as age + 1
   • Convert whole numbers with int()
   • Convert decimals with float()
   • Converting text such as hello gives a ValueError
   • Use str() to join a number to text
   Model answer

   input always gives a string, even if the user types a number. If the user types 7 and the program does age + 1, Python gives a TypeError, because you cannot add a number to a string. To avoid this, convert the input with int(), such as age = int(input("Age? ")), or with float() for decimals. If the user types something like hello, converting it gives a ValueError. To join a number to text for printing, convert it back with str().

This or That

1. The text "12" input always gives text, whatever the user types.
2. int("7") int() makes a whole number. str() makes text.
3. float An int holds whole numbers only. A float holds numbers with decimals.
4. 4 Without quotation marks they are numbers, so + adds them.
5. bool True and False are Booleans. "False" inside quotation marks would be a string.
6. "Age: " + str(12) Convert the number with str() before joining it with +.
7. A ValueError Python cannot turn the word ten into a number.
8. print("Score:", score) A comma works with any type. + needs both sides to be text.

Memory Match

• A 4 int("7"): Turns the text 7 into a whole number
• B 1 float("3.5"): Turns text into a decimal number
• C 5 str(15): Turns a number into text
• D 6 input(): Always gives back text
• E 3 "3" + "4": Joins two strings to make 34
• F 2 bool: True or False