How to Use Lists in Python Notes

by Stilgar

I am going to be detailing out my notes & examples of Python Lists from my Udemy Python Bootcamp.

Lists

  • Ordered sequences that can hold a variety of object types
  • Lists support indexing and slicing
  • Lists are flexible by holding multiple data types i.e
    • my_list =[1,’test’,5,10.2,’Space’]
  • Lists also work with indexing
    • my_list[1] will return “test”
  • You can also concatenate lists
  • You can mutate lists which is a difference from strings
  • Lists Example:
    • indian_schools = [“Zinc School”, “DAV Public School”, “St. Gregorious”]
    • us_schools = [“Davidson Middle School”,”Anderson High”]
    • Concatenating Lists
    • my_schools = indian_schools + us_schools
    • my_schools
    • >> [‘Zinc School’, ‘DAV Public School’, ‘St. Gregorious’, ‘Davidson Middle School’, ‘Anderson High’]
    • Show Item at 0 location
    • my_schools[0] = “Zinc Sr. Secondary Schools”
  • Adding to a List
    • You can add to a list by using append() method
    • my_schools.append(“Wayne State University”)
    • my_schools
    • >> [‘Zinc Sr. Secondary Schools’,’DAV Public School’,’St. Gregorious’, ‘Davidson Middle School’, ‘Anderson High’, ‘Wayne State University’]
  • Removing an Item
    • You can use .pop() method to remove an item from the end of the list if you don’t specify an index value 
    • Example:
    • [‘Zinc Sr. Secondary Schools’,’DAV Public School’,’St. Gregorious’, ‘Davidson Middle School’, ‘Anderson High’]
    • .pop() shows the item that was removed from the end of the list, so you can use the popped item elsewhere if you wanted to
    • .pop(2) will remove an item that is at 2 index value from the list
  • Sort Method
    • Sorts the list in place which means you cannot re-assign the sort to another variable
    • i.e. You cannot do
      • My_sorted_list = new_list.sort()
    • You need to do
      • new_list.sort()
      • My_sorted_list = new_list

You can review my Learning to Code in Python article to see how I got started coding in Python. I am currently working on a few projects that would further advance my Python skills, including building a used-car platform leveraging Scrapy. I am still in early stages, but the goal is to provide insights on used cars, specifically identifying cars that are considered a good+ deal depending on how much the vehicles of the same make/model and price are being sold in the region. Will share the link to the platform once it is out. I am hoping that platform would serve as a significant advancement to my data-science and my python development skills.

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