Question: here is my code and error! please give me a hint

```
import os
def traverse(path, d):
    for item in os.listdir(path):
        item = os.path.join(path, d)
        try:
            traverse(path,d)
        except:
            print (path)

```

my error:

```
traverse ("test",0)
Traceback (most recent call last):
  File "<pyshell#0>", line 1, in <module>
    traverse ("test",0)
  File "C:\Users\Phuchu\Desktop\Python\homework8.py", line 65, in traverse
    for item in os.listdir(path):
FileNotFoundError: [WinError 3] The system cannot find the path specified: 'test\\*.*'

```

Answer: 
It describes the parameters returned, in this case a **vector** of **ints**. The same nomenclature is used for `glTexParameteriv` and `glTexParameterfv` for example, which updates a vector of ints or floats respectively.
It indicates you want to get a value that is an array of integers. The function reference can be found [here](http://www.khronos.org/opengles/sdk/docs/man/xhtml/glGetShaderiv.xml), and as you can see, the return param is a `GLint *`. This is in contrast to functions such as `glGetInternalFormati64v`, which has a return param of `GLint64 *`. I believe, but can't locate at the moment, that there have been functions using the `fv` suffix to denote floats, and possibly others.