1.4 Numbers, Booleans and Strings

1.4 Numbers, Booleans and Strings

After this unit you will: correctly predict whether a value is truthy or falsy, and slice a string at the right positions.

Key points

• Falsy: False None 0 0.0 '' [] () {} set(). Everything else is truthy — even the string "False".
• True + True equals 2 (booleans are numbers).
• Strings are indexed from 0; the slice s[a:b] stops just before b; s[::-1] reverses.
• Strings are immutable: you cannot change individual characters.