Module 4: Python - Data Types

Tipping Points

• Create a list

   majors  = ["Cyber", "CS", "EE", 123, "Math", "Econ"]
  
             

  Note that a Python list does not need to have all elements in the same type.
  • Can a text be converted into a list? - Yes!
  • Then, HOW?
  • Can any other external data sources be formated in a list? For example, streaming data from yahoo.com/finance? How about data from an Excel file?
  • Yes, then HOW?
• Access a list
  • element by an index script

     myMajor = majors[0]
    
               

    What is returned?
  • elements by the range of index script

     myMajor = majors[0:2]
    
               

    What is returned?
  • elements by a subscript of index

     myMajor = majors[0][2]
    
               

    What is returned?

    What about the below?

     myMajor = majors[1][0]
    
               

• Adding to a list
  • .append() - Add an element or a list

    myMajor.append("Pharm")
    print(majors)
    
               

  • .extend() - Extend an element of a list

    Difference between append and extend:

    Try the following

    myMajor.append(['append','append2'])
    myMajor.extend(['extend','extend2'])
    print(majors)
    
               

  • .insert( , ) - Add an element or a list into a specific position. The first parament is the index of a position to insert, and the second parameter is either an element or a list to add.

    myMajor.insert(2, "Math")
    print(majors)
    
               

    Another example:

    moreMj  = ["Music", "Paint"]
    myMajor.insert(3, moreMj)
    print(majors)
    
               

  • + Append two lists

    longMj = majors + moreMj
    print(longMj)
    
               

• Removing an element from a list
  • .remove() - remove the given element

    myMajor.remove(123)
    print(majors)
    
               

    Note the built-in function del() deletes a specified list.

    del(majors[1])
    print(majors)
    
               

  • .pop( ) - remove the element at the specified position

    myMajor.remove(2)
    print(majors)