cs2370 Notes: 02 Programming

Python: Parts of speech #

• Literals:
  • int (type(5))
  • float
  • string (in quotes)
  • boolean
• Variable names
  • (no quotes)
  • starts with a letter, numbers and “_” allowed after
• Operators
  • 3 + 7
• Function calls
  • round(7.3555, 2)
• Expressions:
  • An expression has a value.
  • Literals
  • Operations
  • Some function calls
    • In other languages, “function” may be seperated from “procedure” or “subroutine”.

Arithmetic #

Numbers

>>> 1 + 2
>>> 2 - 4
>>> 3 * 7
>>> 5 / 3

>>> 5 // 3
>>> 5 % 3         # modulus, not remainder

Strings

>>> "zz" + "XX"
>>> "hello " * 3

Making choices #

Conditionals:

• if
• if / else

print("one")

if True:   # False:
    print("two")
#else:
#    print("three")

print("four")

Boolean Expressions:

>>> True and True
>>> True and False
>>> True or True
>>> True or False
>>> not True

• Write out the truth tables for those.