20/06/2024

Week 2 Learning Summary

Week 2 subject 1: Strings

  • String is a Python built-in data type.
  • There are string variables and string literals.
  • string literals are a sequence of characters between a pair of quotation marks.
  • Use of different quotation marks: 
    • escape sequences, 
    • triple quotes for multi-line string literals and,
    • mixed quotation marks.
  • Modify string literals with embedded values and f-strings.
  • Adding and multiplying strings: note the difference between concatenating strings and printing multiple strings.

Week 2 subject 2: Lists

  • List is a Python advance data type.
  • There are list variables and list literals.
  • List is a set of objects, can be of different types.
  • List elements can be accessed with subscripts (which makes Lists iterables), subscript ranges start at 0.
  • You can have lists as elements of lists.  Note one data element is different from one list with only one data element.  Example: “abc” is different from [“abc”].
  • Operating Lists: .append() method, del() function (note they have different syntax).
  • Slicing: [begin:end:step].
  • Splitting strings into lists, joining lists into strings.
  • Adding and multiplying lists.

1 comment:

bin3bin2 said...

Pay special attention to how negative subscripts are used:

>>> str = "do you have money?"
>>> len(str)
18
>>> str[1:10]
'o you hav'
>>> str[:10]
'do you hav'
>>> str[-1:10]
''
>>> str[-1:]
'?'
>>> str[0:-1]
'do you have money'
>>> str[0:-3]
'do you have mon'