text: #!/usr/bin/env python3
  """Python 3.* Quick Reference"""
  
  # Useful docs pages
  
  # Built-In Functions:
  #   https://docs.python.org/3/library/functions.html
  
  # Built-In Types:
  #   https://docs.python.org/3/library/stdtypes.html
  
  
  import sys          # .stdin
  import re           # .search
  
  line = sys.stdin.readline()  # Read single line from std input
  for line in sys.stdin:       # Read each line from stdin, includes \n
  
      # Strings (type str)
      print(ord(line[-1]))
      line = line.rstrip()     # Elim whitespace on right
      line = line.lstrip()     # Elim whitespace on left
      line = line.lower()      # Convert to lower-case
      print(len(line))         # Length of string
      if line:                 # Non-empty strings are truthy
          x = ord(line[0])     # Unicode codepoint
          print(chr(x))        # code -> character (type = str)
      line_rev = line[::-1]    # Reversed line; is a string
  
  # Sets (type set)
  ss = { 22, 33 }
  ss.add(44)                   # Insert in set
  ss.remove(44)                # Delete from set; set must contain element
  ss -= {44}                   # Delete element the set might not contain
  ss.pop()                     # Remove & return an arbitrary element
  ss2 = { 33, 44 }
  ss3 = ss | ss2               # Union
  ss3 = ss & ss2               # Intersection
  ss3 = ss - ss2               # Difference
  ss3 = ss ^ ss2               # Symmetric difference
                               # Above 4: assignment versions also work:
                               #   |=  &=  -=  ^=
  
  # Lists (type list)
  ll = [22, 33]
  ll.append(44)                # Add to end of list
  ll.pop()                     # Delete from end of list
  ll.insert(0, 11)             # Add to beginning of list
  ll.pop(0)                    # Delete from beginning of list
  ll2 = [55, 66]
  ll3 = ll + ll2               # List concatenation
  ll4 = [1, 2, *ll3, 9]        # List unpacking
  
  # F-Strings
  a, b = 1, 2
  print(f"ll[a] + b = {ll[a]+b}, b = {b}")
  
  # Regexps
  st = "aa bbb"
  mo1 = re.search(r"^(a+) (b+)$", st)
  if mo1:                      # Truthy if it matched
      print(mo1[1])            # "aa"
      print(mo1[2])            # "bbb"
  
  