Combining Lists

append( list )

>>> a_list = [1, 2, 3]
 >>> a_list.append( [4, 5] )
 >>> a_list
 [1, 2, 3, [4, 5]]

list( [iterable] )

>>> my_list = list( range(10) )
 >>> my_list
 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

[ ] + [ ]

>>> my_list + [10, 11, 12]
 >>> my_list
 [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]

Extend and Insert

extend( list )

>>> our_list = list( range(1,4) )
 >>> our_list
 [1,2,3]
 >>> our_list.extend( range(5,11) )
 >>> our_list
 [1,2,3,4,5,6,7,8,9,10]

insert(index, list-item)

>>> alpha = list('acdf')
 >>> alpha
 ['a','c','d','f']
 >>> alpha.insert(1,'b')
 >>> alpha.insert(4,'e')
 >>> alpha
 ['a', 'b', 'c', 'd', 'e', 'f', 'e']

Shopping List – Take 3

split(“,”)    strip( )

[shopping_list_3]:
shopping_list = []

def show_help():
  print("\nSeparate each item with a comma.")
  print("Type DONE to quit, SHOW to see the current list, and HELP to get this message.")
  
def show_list():
  count = 1 # Throwaway variable
  for item in shopping_list: 
    print(" {}: {}".format(count, item))
    count += 1
    
print("Give me a list of things you want to shop for.")
show_help()

while True:
  new_stuff = input("> ")
  
  if new_stuff == 'DONE': 
    print("\nHere's your list: ")
    show_list()
    break
  elif new_stuff == 'HELP':
    show_help()
    continue
  elif new_stuff == 'SHOW':
    show_list()
    continue
  else: 
    new_list = new_stuff.split(",")
    index = input("Add this at a certain spot? Press enter for the end of the list, "
                  "or give me a number. Currently {} items in the list.".format( 
        len(shopping_list)))
    if index:
      spot = int(index) - 1
      for item in new_list:
        shopping_list.insert(spot, item.strip())
        spot += 1
    else:
      for item in new_list:
        shopping_list.append(item.strip())