## Tips, Tricks, Ways-of-doing-stuff
## with Lists in Python


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# join() is a string method, but it can "join" a list's elements together,
# BUT ONLY IF the elements are strings or can be first cast as strings.
myList = ['apple', 'a', 'p', 'p', 'l', 'e']
''.join(myList)
# results in:
'appleapple'

myOtherList = ['I', 'enjoy', 'spam']
' '.join(myOtherList)
# results in:
'I enjoy spam'

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## Assign elements of a list to separate variables
myList = [1, 2, 3]
x, y, z = myList

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## Adding elements to lists:
## the differences between list.append(), list1 + list2, and list.extend()

list1 = [1, 2, 3]
list2 = [4, 5, 6]

# append() mutates a list in place.
# DO NOT assign this statement to a variable, you won't get a new list.
# OK:
list1.append(list2) #--> [1, 2, 3, [4, 5, 6]]
# Not OK:
list3 = list1.append(list2)
list3 #--> NoneType

# the + operator creates a new list out of the objects on either side of the +,
# as well as concatenates multiple lists' elements into a "flattened" 1D list.
list3 = list1 + list2
list3 #--> [1, 2, 3, 4, 5, 6]

# extend() mutates a list in place, like append, but unlike append (and like +),
# extend() unpacks and therefore "flattens" its arg (a list or other iterable)
# while also appending it to the first list. BE CAREFUL: extend will unpack ANY
# iterable object, including strings.
myList = [1, 2, 3]
myStr = 'spam'
# e.g.,
myList.extend(['spam'])
# myList --> [1, 2, 3, 'apple']
# HOWEVER...
myList.extend('spam')
# myList --> [1, 2, 3, 'a', 'p', 'p', 'l', 'e']  # maybe not what was intended.

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