如何将元组传递给python函数

Question

I've been trying to pass a tuple to a function that I created earlier, however, I m still not able to make it work. My objective is to pass a tuple containing a list of path+file form which I want to discover the size and print it out.

Here's my code

EXl = ('C:\\vd36e404.vdb','C:\\vd368c03.vdb')

def fileF(EXl):
    import os
    filesize = os.path.getsize(EXl)
    print (filesize);

fileF(EXl)

These are the errors:

Traceback (most recent call last):
  File "C:\Documents and Settings\Administrator\workspace\test1py\testcallMyF.py", line 13, in <module>
    fileF(EXl)
  File "C:\Documents and Settings\Administrator\workspace\test1py\testcallMyF.py", line 9, in fileF
    filesize= os.path.getsize(EXl)
  File "C:\Python27\lib\genericpath.py", line 49, in getsize
    return os.stat(filename).st_size
TypeError: coercing to Unicode: need string or buffer, tuple found

Could anyone explain to me why?(I'm using Python 2.7.2)

Answer 1

You're successfully passing the tuple to your own function. But os.path.getsize() doesn't accept tuples, it only accepts individual strings.

Also, this question is a bit confusing because your example isn't a path + file tuple, which would be something like ('C:\\\\', 'vd36e404.vdb') .

To handle something like that, you could do this:

import os

def fileF(EXl):
    filesize= os.path.getsize(EXl[0] + EXl[1])
    print (filesize);

If you want to print values for multiple paths, do as Bing Hsu says, and use a for loop. Or use a list comprehension:

def fileF(EXl):
    filesizes = [os.path.getsize(x) for x in EXl]
    print filesizes

Or if you want to, say, return another tuple:

def fileF(EXl):
    return tuple(os.path.getsize(x) for x in EXl)

Answer 2

import   os

for xxx in EXl:
    filesize= os.path.getsize(xxx)
    print (filesize);

Answer 3

A way more elegant example:

map(fileF, EX1)

This will actually call fileF separately with each of the elements in EX1. And of course, this is equivalent to

for element in EX1:
    fileF(element)

Just looks prettier.