练习代码

the_count = [1, 2, 3, 4, 5]
fruits = ['apples', 'oranges', 'pears', 'apricots']
change = [1, 'pennies', 2, 'dimes', 3, 'quarters']

# this first kind of for-loop goes through a list
for number in the_count:
    print(f"This is count {number}")

# same as above
for fruit in fruits:
    print(f"A fruit of type: {fruit}")

# also we can go through mixed lists too
# notice we have to use {} since we don't know what's in it
for i in change:
    print(f"I got {i}")

# we can also build lists, first start with an empty one.
elements = []

# then use the range function to do 0 to 5 counts
for i in range(0, 6):
    print(f"Adding {i} to the list.")
    # append is a function that lists understand
    elements.append(i)

# now we can print them out too
for i in elements:
    print(f"Element was: {i}")

Study Drills

1. Take a look at how you used range. Look up the range function to understand it.

   range doc

2. Could you have avoided that for-loop entirely on line 22 and just assigned range(0,6) directly to elements?

   可以用list()函数，elements = list(range(0, 6))

3. Find the Python documentation on lists and read about them. What other operations can you do to lists besides append?

sequence