array = [ 1 , 2 , 5 , 3 , 6 , 8 , 4 ]
[ 1 , 2 , 5 , 3 , 6 , 8 , 4 ]
( 0 , 1 , 2 , 3 , 4 , 5 , 6 )
( - 7 , - 6 , - 5 , - 4 , - 3 , - 2 , - 1 )
array[ 0 :]
[ 1 , 2 , 5 , 3 , 6 , 8 , 4 ]
array[ 1 :]
[ 2 , 5 , 3 , 6 , 8 , 4 ]
array[: - 1 ]
[ 1 , 2 , 5 , 3 , 6 , 8 ]
array[ 3 : - 3 ]
[ 3 ]
for
loop
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 "This is count %d" % number
# same as above
for fruit in fruits:
print "A fruit of type: %s" % fruit
# also we can go through mixed lists too
# notice we have to use %r since we don't know what's in it
for i in change:
print "I got %r" % 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 "Adding %d to the list." % i
# append is a function that lists understand
elements.append(i)
# now we can print them out too
for i in elements:
print "Element was: %d" % i
输出
This is count 1
This is count 2
This is count 3
This is count 4
This is count 5
A fruit of type: apples
A fruit of type: oranges
A fruit of type: pears
A fruit of type: apricots
I got 1
I got 'pennies'
I got 2
I got 'dimes'
I got 3
I got 'quarters'
Adding 0 to the list.
Adding 1 to the list.
Adding 2 to the list.
Adding 3 to the list.
Adding 4 to the list.
Adding 5 to the list.
Element was: 0
Element was: 1
Element was: 2
Element was: 3
Element was: 4
Element was: 5
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