Data Structures 810:052 Python Collections

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Data Structures810052Python Collections
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Getting Started

• You were supposed to
• Read through several sections of the textbook
• Read the syllabus
• Finish yesterdays lab
• Any questions?

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One quick observation

• Yesterday in my tutorial I showed you the
  following method for printing
• print The answer is str(answer)
• print firstName lastName
• Some of you started using this instead
• print The answer is,str(answer)
• print firstName , lastName
• While this last one LOOKS preferable, Im going
  to strongly encourage you to follow my method
• Problems arise later when you try to do file
  writing

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Formatting Strings

• But there is another way to do it. Rather than
  saying
• print The area of a circle with a radius of
  radius is area
• You might say
• print The area of a circle with a radius of i
  is .2f (radius, area)

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Suggestions before you go much further

• Download and install python (version 2.5.4 is
  what is in the labs but 2.6.2 should work equally
  as well) on your home machine.
• www.python.org
• Obtain a copy of the python quick reference guide
  (60 pages)
• rgruet.free.fr

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Quick Review of Yesterday

• Python has five basic date types
• Integer - int()
• Long - long()
• Float - float()
• String - str()
• Boolean bool()
• bool(0) -gt False
• bool(1) - gt True
• bool(78) -gt True

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Moving on

• Lists
• Range
• Iteration
• Strings as lists
• Tuples
• Dictionary
• And if time how python handles values in memory

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Lists

• A Python list is an ordered, mutable, collection
  of comma-separated values of any data type
  enclosed in square brackets
• faculty Schafer , Fienup, East ,
  Drake
• rhyme 1, 2, buckle, your , shoe
• empty this is an empty list

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Methods available to all collections