python 基础知识学习

1、装饰器

def warp(x):
import time
def f(func):
def call_fun(*args,**kwargs):
start_time = time.time()
print 'func====',func,"args===",args,'kwargs===',kwargs
func(*args,**kwargs)
end_time = time.time()
if end_time - start_time>x:
print 'bad'
else:
print 'goods'
return call_fun
return f

@warp(3)
def ff(*args,**kwargs):
import time
print 'call func'
time.sleep(4)

说明：装饰器的调用原理类似如下：

warp(3)(ff)(*args,**kwargs)

 if __name__ == "__main__":
ff("a","b")

2、传递参数

f(a,b,c="1",d="2",*args,**kwargs):

pass

f("a","b","c",c="dd")

f("a","b",c="dd","9")

3、继承

class A(object):

x= 1

class B(A):

pass

class C(A):

pass

print A.x,B.x,C.x

B.x = 2

print A.x,B.x,C.x

A.x = 3

print A.x,B.x,C.x

4、列表排序

l = [23,3,4,3,2,2,1,1,]

sorted(list_a,lambda x1,x2:x1<x2 and 1  or -1)

list_a.sort(lambda x,y:x<y and -1 or 1)

5、filter 找出索引为基数的数

Help on built-in function filter in module __builtin__:

filter(...)

    filter(function or None, sequence) -> list, tuple, or string

    

    Return those items of sequence for which function(item) is true.  If

    function is None, return the items that are true.  If sequence is a tuple

    or string, return the same type, else return a list.

<pre name="code" class="python">list_a = [12,213,22,2,2,2,22,2,2,32,]

[elem[1] for elem in  filter(lambda x:x[0]%2!=0, zip(range(1,len(list_a)),list_a))]

6、快速排序

def quick_sort(sort_list,result):
if len(sort_list) ==1:
return sort_list

key_elem = sort_list.pop(0)
left_list = []
right_list = []
for e in sort_list:
if e>=key_elem:
right_list.append(e)
else:
left_list.append(e)

temp_result1 = []
temp_result2 = []
if left_list:
quick_sort(left_list,temp_result1)
if right_list:
quick_sort(right_list,temp_result2)

result.extend(temp_result1)
result.append(key_elem)
result.extend(temp_result2)

return result

if __name__ == "__main__":
result = []
quick_sort([1,3,9,8,7,6,5,3,2,1,0,-9,123],result)

print 'result============',result