1、函数定义：
>>> deffibs(n):
... fib = [0, 1]
... for i in range(n-2):
... fib.append(fib[-2] + fib[-1])
... return fib
...
>>> printfibs(10)
[0, 1, 1, 2, 3, 5,8, 13, 21, 34]
2、默认参数
def ask_ok(prompt,retries=4, complaint='Yes or no, please!'):
while True:
ok= raw_input(prompt)
ifok in ('y', 'ye', 'yes'):
return True
ifok in ('n', 'no', 'nop', 'nope'):
return False
retries= retries - 1
ifretries < 0:
raise IOError('refusenik user')
printcomplaint
>>>ask_ok('Do you really want to quit?')
Do you really wantto quit?yes
True
3、关键字参数
def parrot(voltage,state='a stiff', action='voom', type='Norwegian Blue'):
print "-- This parrot wouldn't",action,
print "if you put", voltage,"volts through it."
print "-- Lovely plumage, the",type
print "-- It's", state,"!"
parrot(1000) # 1个位置参数
>>>kw_argument.parrot(10000)
-- This parrotwouldn't voom if you put 10000 volts through it.
-- Lovely plumage,the Norwegian Blue
-- It's a stiff !
parrot(voltage=1000) # 1个关键字参数
>>>kw_argument.parrot(voltage=10000)
-- This parrotwouldn't voom if you put 10000 volts through it.
-- Lovely plumage,the Norwegian Blue
-- It's a stiff !
parrot(voltage=1000000, action='VOOOOOM') # 2个关键字参数
>>>kw_argument.parrot(voltage=1000000,action='VOOOOOOOM')
-- This parrotwouldn't VOOOOOOOM if you put 1000000 volts through it.
-- Lovely plumage,the Norwegian Blue
-- It's a stiff !
parrot(action='VOOOOOM', voltage=1000000) # 2个关键字参数
>>>kw_argument.parrot(action='VOOOOOOOM',voltage=1000000)
-- This parrotwouldn't VOOOOOOOM if you put 1000000 volts through it.
-- Lovely plumage,the Norwegian Blue
-- It's a stiff !
parrot('a million', 'bereft of life', 'jump') #3 个位置参数
>>>kw_argument.parrot('a million', 'bereft of life', 'jump')
-- This parrotwouldn't jump if you put a million volts through it.
-- Lovely plumage,the Norwegian Blue
-- It's bereft oflife !
parrot('a thousand', state='pushing up the daisies') # 1个位置参数
>>>kw_argument.parrot('a thousand', state='pushing up the daisies')
-- This parrotwouldn't voom if you put a thousand volts through it.
-- Lovely plumage,the Norwegian Blue
-- It's pushing upthe daisies !
4、收集多余参数
ubuntu@ubuntu:~$ catmulti_argument.py
#!/usr/bin/envpython
def cheeseshop(kind,*arguments, **keywords):
print "-- Do you have any", kind,"?"
print "-- I'm sorry, we're all outof", kind
for arg in arguments:
printarg
print "-" * 40
keys = sorted(keywords.keys())
for kw in keys:
printkw, ":", keywords[kw]
>>>multi_argument.cheeseshop("Limburger", "It's very runny,sir.",
... "It'sreally very, very runny, sir.",
...shopkeeper="Michael Palin",
...client="John Cleese",
...sketch="Cheese Shop Sketch")
-- Do you have anyLimburger ?
-- I'm sorry, we'reall out of Limburger
It's very runny,sir.
It's really very,very runny, sir.
----------------------------------------
client : John Cleese
shopkeeper : MichaelPalin
sketch : Cheese ShopSketch