Summary - Input and output
- Python course
- Beginner
- Lesson 99/116
- 5 min
Combine input, conversion and formatting to write an interactive menu.
Summary - Input and output
In this group you learned four core tools:
- input() — reads a string from the user
- int() / float() — convert a string to a number
- print() sep/end — format the output
- f-string — embeds an expression in a string
- sys.argv — gives command-line arguments
Now you will do two short tasks that combine them: one with interactive input, one with a command-line argument.
Practice Interactive age calculator
Assign input("Ad: ") to name (user types Ayşe). Assign int(input("Yaş: ")) to age (user types 30). Then write print(f"{name} gelecek yıl {age + 1} yaşında").
Starter code
# read name and age
# print next year's age with f-stringSample solution
name = input("Ad: ")
age = int(input("Yaş: "))
print(f"{name} gelecek yıl {age + 1} yaşında")Expected output
Ad: Yaş: Ayşe gelecek yıl 31 yaşında
Practice Print double with sys.argv
Write import sys. Assign sys.argv[1] if len(sys.argv) > 1 else "5" to val. Assign int(val) to num. Then write print(num * 2). The script runs with no arguments.
Starter code
# bring in the sys module
# use "5" if no argument, convert to int
# double and printSample solution
import sys
val = sys.argv[1] if len(sys.argv) > 1 else "5"
num = int(val)
print(num * 2)Expected output
10
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 How are input() and int() used together?
- int(input(...)) Correct answer
- int.input(...)
- input(int(...))
- input->int(...)
Explanation: int(input(...)) works outside-in: first input is read, then converted.
2 Complete the print sep
print("a", "b", "c", sep=____)print("a", "b", "c", sep=",")Explanation: sep="," joins values with commas.