python语法——数据结构（代码）

源网页：http://woodpecker.org.cn/abyteofpython_cn/chinese/ch09s02.html

列表

#!/usr/bin/python
# Filename: using_list.py

# This is my shopping list
shoplist = ['apple', 'mango','carrot', 'banana']

print 'I have', len(shoplist),'items to purchase.'

print 'These items are:',# Notice the comma at end of the line
for item in shoplist:
    print item,

print '\nI also have to buy rice.'
shoplist.append('rice')
print 'My shopping list is now', shoplist

print 'I will sort my list now'
shoplist.sort()
print 'Sorted shopping list is', shoplist

print 'The first item I will buy is', shoplist[0]
olditem = shoplist[0]
del shoplist[0]
print 'I bought the', olditem
print 'My shopping list is now', shoplist

输出

$ python using_list.py
I have 4 items to purchase.
These items are: apple mango carrot banana
I also have to buy rice.
My shopping list is now ['apple', 'mango', 'carrot', 'banana', 'rice']
I will sort my list now
Sorted shopping list is ['apple', 'banana', 'carrot', 'mango', 'rice']
The first item I will buy is apple
I bought the apple
My shopping list is now ['banana', 'carrot', 'mango', 'rice']

元组

#!/usr/bin/python
# Filename: using_tuple.py

zoo = ('wolf', 'elephant','penguin')
print 'Number of animals in the zoo is',len(zoo)

new_zoo = ('monkey', 'dolphin', zoo)
print 'Number of animals in the new zoo is',len(new_zoo)
print 'All animals in new zoo are', new_zoo
print 'Animals brought from old zoo are', new_zoo[2]
print 'Last animal brought from old zoo is', new_zoo[2][2]

使用new_zoo[2][2]来访问new_zoo元组的第三个项目的第三个项目。


输出

$ python using_tuple.py
Number of animals in the zoo is 3
Number of animals in the new zoo is 3
All animals in new zoo are ('monkey', 'dolphin', ('wolf', 'elephant', 'penguin'))
Animals brought from old zoo are ('wolf', 'elephant', 'penguin')
Last animal brought from old zoo is penguin

字典

#!/usr/bin/python
# Filename: using_dict.py

# 'ab' is short for 'a'ddress'b'ook

ab = {       'Swaroop'   : '[e-mail]',
             'Larry'     : '[e-mail]',
             'Matsumoto' : '[e-mail]',
             'Spammer'   : '[e-mail]'
     }

print "Swaroop's address is %s" % ab['Swaroop']

# Adding a key/value pair
ab['Guido'] = '[e-mail]'

# Deleting a key/value pair
del ab['Spammer']

print '\nThere are %d contacts in the address-book\n'% len(ab)
for name, address in ab.items():
    print 'Contact %s at %s' % (name, address)

if 'Guido' inab: # OR ab.has_key('Guido')
    print "\nGuido's address is %s" % ab['Guido']

输出

$ python using_dict.py
Swaroop's address is [e-mail]

There are 4 contacts in the address-book

Contact Swaroop at [e-mail]
Contact Matsumoto at [e-mail]
Contact Larry at [e-mail]
Contact Guido at [e-mail]

Guido's address is [e-mail]

序列

#!/usr/bin/python
# Filename: seq.py

shoplist = ['apple', 'mango','carrot', 'banana']

# Indexing or 'Subscription' operation
print 'Item 0 is', shoplist[0]
print 'Item 1 is', shoplist[1]
print 'Item 2 is', shoplist[2]
print 'Item 3 is', shoplist[3]
print 'Item -1 is', shoplist[-1]
print 'Item -2 is', shoplist[-2]

# Slicing on a list
print 'Item 1 to 3 is', shoplist[1:3]
print 'Item 2 to end is', shoplist[2:]
print 'Item 1 to -1 is', shoplist[1:-1]
print 'Item start to end is', shoplist[:]

# Slicing on a string
name = 'swaroop'
print 'characters 1 to 3 is', name[1:3]
print 'characters 2 to end is', name[2:]
print 'characters 1 to -1 is', name[1:-1]
print 'characters start to end is', name[:]

输出

$ python seq.py
Item 0 is apple
Item 1 is mango
Item 2 is carrot
Item 3 is banana
Item -1 is banana
Item -2 is carrot
Item 1 to 3 is ['mango', 'carrot']
Item 2 to end is ['carrot', 'banana']
Item 1 to -1 is ['mango', 'carrot']
Item start to end is ['apple', 'mango', 'carrot', 'banana']
characters 1 to 3 is wa
characters 2 to end is aroop
characters 1 to -1 is waroo
characters start to end is swaroop

对象与参考

#!/usr/bin/python
# Filename: reference.py

print 'Simple Assignment'
shoplist = ['apple', 'mango','carrot', 'banana']
mylist = shoplist # mylist is just another name pointing to the same object!

del shoplist[0]

print 'shoplist is', shoplist
print 'mylist is', mylist
# notice that both shoplist and mylist both print the same list without
# the 'apple' confirming that they point to the same object

print 'Copy by making a full slice'
mylist = shoplist[:] # make a copy by doing a full slice
del mylist[0]# remove first item

print 'shoplist is', shoplist
print 'mylist is', mylist
# notice that now the two lists are different

输出

$ python reference.py
Simple Assignment
shoplist is ['mango', 'carrot', 'banana']
mylist is ['mango', 'carrot', 'banana']
Copy by making a full slice
shoplist is ['mango', 'carrot', 'banana']
mylist is ['carrot', 'banana']

字符串

name = 'Swaroop' # This is a string object

if name.startswith('Swa'):
    print 'Yes, the string starts with "Swa"'

if 'a' in name:
    print 'Yes, it contains the string "a"'

if name.find('war') !=-1:
    print 'Yes, it contains the string "war"'

delimiter = '_*_'
mylist = ['Brazil', 'Russia','India', 'China']
print delimiter.join(mylist)

输出

$ python str_methods.py
Yes, the string starts with "Swa"
Yes, it contains the string "a"
Yes, it contains the string "war"
Brazil_*_Russia_*_India_*_China