Python · Lesson 4 of 9

Conditions

if, elif, else, comparison operators and and / or / not.

Conditions let your program choose. Python checks each test from the top and runs the first block whose condition is true.

if score >= 75:
    print("Shortlisted")
elif score >= 50:
    print("Waitlisted")
else:
    print("Not selected")

Note the colon : at the end of each test and the indented block underneath.

Comparisons: == != < > <= >=. Combine with and, or, not. Check membership with in: "sql" in skills.

Try it yourself

Code editor

Press Run to see the output.

Edit and press Run (or Ctrl/⌘ + Enter). Python runs in your browser — the first run downloads the Python engine and takes a few seconds.

Which keyword checks another condition after if?

else if elif elseif then

Write a program that takes a marks variable and prints Distinction (≥ 80), First class (≥ 60), Pass (≥ 40) or Fail.

What values are 'falsy' in Python?

False, None, 0, 0.0, empty string '', and empty containers such as [], {}, set() and (). Everything else is truthy.

What is the difference between == and is?

== compares values; is checks whether two names point to the same object. Use is mainly for None checks: if x is None.