Data conversion gives a value a different type so you can use it in a new way. In Python, put the value inside the name of the type you want: int(...), float(...), or str(...). Use type(...) in the console when you want to check a value’s type. section 5.3
Try these small conversions:
- float(4) gives 4.0; int("4") gives the number 4 rather than the string "4". section 5.3
- str(3.5) gives "3.5". int(3.94) gives 3: the part after the decimal point is removed. section 5.3
- int(False) gives 0 and int(True) gives 1. But int("a") causes an error because "a" is not a number. section 5.3
Turn typed input into a number
user_input = input("Enter a number: ") num = int(user_input) print(num * num) First, input() waits for an answer and returns a string, even if the user types digits. Next, int(...) converts that string to a number. Only then does the program multiply it. If the answer is not a numeric string, the conversion fails. section 11.2 section 5.3
Make an index from a division result
halfway = int(len(name) / 2) first_half = name[0:halfway] Dividing an odd name length by 2 produces a decimal value, which cannot serve as a string index. Converting it with int(...) gives a whole-number halfway point; for a five-letter name, the first slice has two letters. section 12.3
Keep type conversion separate from changing what a number measures. For example, a minutes-to-hours program divides by 60 to change units, then uses int(...) to turn the decimal hours result into a whole-number hours value. Quick check: what do int(0.5) and str(True) produce? section 6.3 section 5.3
