Sequences

  • A set of items indexed by ascending integer values.
  • Indexing is 0-based (0 refers to the first item).
  • Negative indexes (usually) are relative to the length of the sequence (-1 refers to the last item).
  • The built-in function len() returns the number of items in a sequence.

Strings

  • Strings can be enclosed in single quotes or double quotes.
  • Strings are immutable (read-only).

Raw strings

  • Unformatted
  • Precede the string with the letter "r"  (i.e.  r"Single \n line \n")
  • Escape characters are not processed.

Multi-line strings

  • Append a backslash character to the end of every non-final line.
  • Enclose the string in a series of three consecutive single or double quotes.
str = "Multi-line" \
      "string"
str = """
Multi-line
string
"""
str = '''
Multi-line
string
'''

Tuples

( expr [, expr]* )
  • Comma-separated, parentheses-enclosed list of expressions.
  • Tuples are immutable (read-only).
()     # 0 items
(1,)   # 1 item
(1,2)  # 2 items

Lists

[ expr [, expr]* ]
  • Comma-separated, bracket-enclosed list of expressions.
  • Lists are mutable (writeable).
[]     # 0 items
[1]    # 1 item
[1,2]  # 2 items

Slicings

seq [ start_index : less_than_index ]

    # start_index: defaults to '0' (starting from the first item).
    # less_than_index: defaults to the length of the sequence (ending with the last item).
  • Selects a range of items in a sequence, up to, but not including, the last item specified.
seq[2:4]   # [2..3]
seq[2:]    # [2..end]
seq[:4]    # [0..3]
seq[:]     # [0..end]