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cs2370 Notes: 03 Programming

··2 mins

General Advice #

  • Attendence is strongly recommended.
  • Also, eating and sleeping.

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.

Example:

aa = int(input("aa = "))
bb = int(input("aa = "))

if aa > 10 and bb > 10:
   print("Both")

if aa > 10 or bb > 10:
   print("Either)
   
if aa <= 10 && bb <= 10:
    print("Neither")

Example 2:

word = input("enter word: ")

if word < "n":
    print(word.capitalize())
else:
    print(word)

While loops:

  • while
  • let’s write a script that left-pads strings to 40 chars in a loop