python中的else

1 : 最常用的形式自然是if--else

　　if pd == "cool":

　　　　print "okay camera"

　　elif pd == "pussy":

　　　　print "yes, ure right"

　　else:

　　　　print "god is anywhere"

　　

2 : try---except----else----finally

　　这里的逻辑是弱try没有抛出异常，就会执行else中的语句

　　try:

　　　　find_element_by_id("xxx")

　　except ElementNotExist:

　　　　pass

　　else:

　　　　assertFail("should not have this element")

　　finally:

　　　　log("complete the test of no element xxx")

 

3: for---else(结合break使用)

　　使用一个文档的例子　

 　　for n in range(2, 10):
...     for x in range(2, n):
...         if n % x == 0:
...             print n, 'equals', x, '*', n/x
...             break
...     else:
...         # loop fell through without finding a factor
...         print n, 'is a prime number'

　　这里提及下continue的用法。注意其核心是跳过此次循环，即是continue之后的语句将不再执行：

for num in range(2, 10):
    if num % 2 == 0:
        print "Found an even number", num
        continue
    print "Found a number", num
输出：
Found an even number 2
Found a number 3
Found an even number 4
Found a number 5
Found an even number 6
Found a number 7
Found an even number 8
Found a number 9