Does python yield imply continue?

I have a for loop that checks a series of conditions. O开发者_如何学编程n each iteration, it should yield output for only one of the conditions. The final yield is a default, in case none of the conditions are true. Do I have to put a continue after each block of yields?

def function():
    for ii in aa:
       if condition1(ii):
           yield something1
           yield something2
           yield something3
           continue

       if condition2(ii):
           yield something4
           continue

       #default
       yield something5
       continue

---

NO, yield doesn't imply continue, it just starts at next line, next time. A simple example demonstrates that

def f():
    for i in range(3):
        yield i
        print i,

list(f())

This prints 0,1,2 but if yield continues, it won't

---

Instead of using the continue statement I would suggest using the elif and else statments:

def function():
    for ii in aa:
       if condition1(ii):
           yield something1
           yield something2
           yield something3

       elif condition2(ii):
           yield something4

       else: #default
           yield something5

This seems much more readable to me

---

yield in Python stops execution and returns the value. When the iterator is invoked again it continues execution directly after the yield statement. For instance, a generator defined as:

def function():
    yield 1
    yield 2

would return 1 then 2 sequentially. In other words, the continue is required. However, in this instance, elif and else as flashk described are definitely the right tools.

---

continue skips the remaining code block, but the code block after yield is executed when next() is called again on the generator. yield acts like pausing execution at certain point.

---

This way is more clear, hope it helps, also thanks Anurag Uniyal.

def f():
    for i in range(3):
        yield i
        print(i+10)

list(f())

----------- after run ------------

10
11
12
[0, 1, 2]

---

If the something is simple value and conditions are checks for equality, I would prefer to make this "case structure" dictionary lookup:

ii_dict={'a':('somethinga1','somethinga2','somethinga3'),'b':('somethingb1',)}
ii_default = ('somethingdefault',)
aa='abeabbacd'

def function():
    return (value
           for ii in aa
           for value in (ii_dict[ii] if ii in ii_dict else ii_default))

for something in function(): print something