从 function 返回列表的元素

Question

I want to define a function that takes a list as its argument and then returns the elements in order.

For example:

def iterator(lis):
    for e in range(len(lis)):
        return lis[e]

l=input("Enter list elements:").split()
x=iterator(l)
print(x)

But this just returns the first value of the list as:

Enter list elements:12 23 34
12

How can I print all the values in successive lines?

Answer 1

You can use yield in order to build a generator, here's the official documentation about Generators

What is a generator in Python?

A Python generator is a function which returns a generator iterator (just an object we can iterate over) by calling yield. yield may be called with a value, in which case that value is treated as the "generated" value.

I also want to share an example, be sure to read the comments:

def iterator(lis):
    for e in range(len(lis)):
        yield lis[e]

l=input("Enter list elements:").split()

# A generator returns an Iterable so you should
# loop to print
for number in iterator(l):
    print(number)

# Or use list
result = list(iterator(l))
print(result)

Output
1
2
3
['1', '2', '3']

Answer 2

You probably want yield , as return causes the function call to end immediately. But yield just produces another iterator; you still need to iterate over the result to print them all, rather than simply printing the iterator itself.

def iterator(lis):
    for e in range(len(lis)):
        yield lis[e]

...
for element in x:
    print(element)

Of course, you are pretty much just reimplementing the existing list iterator here; an equivalent definition would be

def iterator(lis):
    yield from lis

What you might want instead is to do something like

x = '\n'.join(l)
print(x)

which creates a string by iterating over l and joining the elements using \n . The resulting multiline string can then be printed.

Answer 3

It will print only one element if you do return

def iterator(lis):
    for e in range(len(lis)):
        return lis[e]
l=input("Enter list elements:").split()
x=iterator(l)
for y in x: print(y)

Answer 4

Use: def iterator(list): for e in range(len(list)): a= list[e] print(a) l=a,b,c=input().split() a=iterator(l)

Answer 5

Use:

[print(i) for i in input("Enter list elements:").split(" ")]

Answer 6

return causes the function to stop after it hits the statement. So your for loop only ever runs once.

You could use yield as mentioned in the other answers, but I really don't think you need a function in this situation. Because the function is just going to return the list that it took as an argument. What you should do is something like this:

i = input("Enter list elements: ").split()
for x in i:
   print(x)

It's that simple.

Answer 7

def iterator(lis):
    for e in range(len(lis)):
        print( lis[e])

l=input("Enter list elements:").split()
iterator(l)

if you want to do some operations for each item in the list, then you should accomodate those within the function.

Answer 8

Use of print instead of return will give you the expected output..try it once