Python字典在for循环中具有三个值

Question

Using python I have some code that looks like this:

for (key, value) in files:
    ...

A working list for the above could be:

files = [(
   'key1', 'value1'
), ...]

I now found this code:

for (key, filename, value) in files:
    ...

How would the dict look for me to get key , filename and value ?

Answer 1

Do you want a dict or a list like you have supplied? If you want to keep it as a list you could just extend the tuple to have three items instead of two like so. I assume from your wording you want to know what the files variable would look like in order to fit with that loop. This should suffice:

files = [
        ('key1', 'file1', 'value1'),
        ('key2', 'file2', 'value2'),
        ('key3', 'file3', 'value3')
        ]

for (key, file, value) in files:
    print key, file, value

>>key1 file1 value1
>>key2 file2 value2
>>key3 file3 value3

If you want it to be a dict you would probably want to format it like this:

files = {
        'key1': ('file1', 'value1'),
        'key2': ('file2', 'value2'),
        'key3': ('file3', 'value3')
        }

for key, value in files.iteritems():
    print key, value[0], value[1]

>>key3 file3 value3
>>key2 file2 value2
>>key1 file1 value1

However be aware that dict's won't keep the order of the items if that is important to you.