Review of Python — Part 1A

• Numbers and numerical operators

  + * - / // % **

• Functions
  • definitions
  • calls
• Control
  • if/elif/.../else
  • for
  • while
  • logical operators: and, or, not
  • Boolean values True, False
  • Boolean interpretation of other types of values
• Input and output
  • input("prompt? ") — is evaluated in Python 2, not evaluated in Python 3
  • raw_input("prompt? ") — in Python 2 is not evaluated, returns a string; not available in Python 3 (use input)
  • float, int, eval, etc.
  • print
    • formatting
      • where do we look up details?
  • Sequences (includes strings and lists)
    • Strings are immutable sequences of characters delimited with "" or ''
    • Lists are mutable sequences of anything delimited with []
    • Tuples are like lists but immutable, delimited with ()
    • Common operations:
      • indexing
      • slicing
      • * number
      • + string or list
      • len function → length of sequences
    • Lists specifically:
      • Methods: append, ...
        • where do we look up details?
      • Deleting: del alist[i]
    • Tuples — like lists, but immutable
      • Special notation for a tuple of one element: ('a',)

Example

→ A Python 3 session

Suggested Exercises

1. Write a Python function with one argument, eggs, which uses an "if" statement to prints "fine" if the value of eggs is 29 or greater, prints "really?" if eggs is less than 29 but not less than 15, and prints "shucks" if eggs is less than 15.
2. Write a Python "for" statement which prints "Happy birthday!" 9 times.
3. Do the same with a "while" statement.
4. Write a Python function which, given an argument names which is a list of strings, prints "Happy birthday, ⟨name⟩" for each ⟨name⟩ in names. For example, if names contains James and Jane, the output would be

   Happy birthday, James
   Happy birthday, Jane

→ Solutions