Data Structures in Python

• Tuples
  • Tuples are immutable
    • They can not be changed.
    • This is (I assume) in support of functional programming.
    • They don't like to change data values.
  • a = (3,4,5)
    • a[0]
    • a[0] = 4
  • Common Operations
  • I really don't use tuples that often.
• Sets
  • These are sets
    • IE they only have one of each item.
    • s = {1, 1, 2, 3, 4, 4, 4}
  • union, and intersection
    • As methods .union, .intersection
    • As operators |, &
  • set() produces an empty set.
  • Using a set, can you produce a list of unique words in a file?
    • string.lower() and string.isalpha()
    • string.split(), string.strip()
    • sorted()
    • set.union
• Lists
  • An 0 - indexed array
  • [] declares an empty list
  • .append, .extend
• Dictionaries
  • {}
  • {'key':value, 'key':value}
  • .keys(), .values()
• If you want to make a module
  • Just put it into a file.
  • import file brings the entire thing in
    • But you need to dereference filename.function
  • import file as shortname
    • shortname.function
  • from file import name
  • from file import *
  • if __name__ == "__main__":