9

I am following the tutorial(http://pyusb.sourceforge.net/docs/1.0/tutorial.html)

I am on windows xp sp3, my python version is 2.7 and I downloaded and installed the pyusb-1.0.0-a1.zip

and libusb-win32-bin-1.2.4.0.zip

import usb

works fine

but 

import usb.core

doesn't working at all

it says 

Traceback (most recent call last):
  File "D:\py\usb.py", line 1, in <module>
    from usb import core
  File "D:\py\usb.py", line 1, in <module>
    from usb import core
ImportError: cannot import name core

any solution?

thanks!

p.s. "from usb import core" this make

Traceback (most recent call last):
  File "D:\py\usb.py", line 1, in <module>
    from usb import core
  File "D:\py\usb.py", line 1, in <module>
    from usb import core
ImportError: cannot import name core

full source code is here

from usb import core
#find device
dev = usb.core.find(idVendor=0x1516, idProduct=0x8628)
#found?
if dev is None :
        raise ValueError('device not found')

#set the active config. with no args, the first config will be the active one

dev.set_configuration()

#get an end point instance
ep = usb.util.find_descriptor(
    dev.get_interface_altsetting(), #first interface
    #match the first Out Endpoint
    custom_match = \
        lambda e: \
            usb.util.endpoint_direction(e.bEndpointAddress) == \
            usb.util.ENDPOINT_OUT)
assert ep is not None

while(1):
    ep.write(0x5553424350DDBC880000000000000600000000000000000000000000000000)
    ep.write(0x5553425350ddbc880000000000)
nemo
  • 55,207
  • 13
  • 135
  • 135
kim taeyun
  • 1,837
  • 2
  • 24
  • 49

4 Answers4

12

Your question says you're using 1.0, but I had the same symptoms as you did, so I'll put this here for future search-engine users.

If you can import usb but not import usb.core you may be running python-usb 0.x instead of 1.0.

https://github.com/walac/pyusb

ryanbraganza
  • 16,863
  • 3
  • 17
  • 24
4

I suppose that "D:\py\usb.py" is the name of your py test program.

Unfortunately this make confusion to the py compiler due to the fact that usb is also the name of the module.

Change it in usbtest.py and everything works

Roberto
  • 41
  • 1
4

In both cases error is:

Traceback (most recent call last):
  File "D:\py\usb.py", line 1, in <module>

which means it has file usb.py in PATH earlier (probably in . which is D:\py\ in this case) than path to python modules.

Did you install this module properly? Try rename this usb.py file to something else, you'll see if the error becomes "ImportError: No module named usb". Also check Python install path (something like C:\Python27\) for usb folder i.e. <python_path>\lib\site-packages\usb\core.py.

Grzegorz Rożniecki
  • 27,415
  • 11
  • 90
  • 112
  • i change the directory to desktop, name to usb2.py it says Traceback (most recent call last): File "C:/Documents and Settings/kty1104/Desktop/usb2.py", line 3, in dev = usb.core.find(idVendor=0x1516, idProduct=0x8628) NameError: name 'usb' is not defined – kim taeyun Jun 02 '11 at 10:45
  • thanks it works fine now is it normal that "import usb" doesn't work but "import usb.core" works? – kim taeyun Jun 02 '11 at 10:47
  • Try open interactive Python shell (or even better install and use [IPython](http://ipython.scipy.org)) and do: `import usb`, next `help(usb)` (or `usb?` in IPython), find line `FILE` and check if usb module is in given path (shold be a directory called `usb*` with at least __init__.py file and `core.py` file). – Grzegorz Rożniecki Jun 02 '11 at 11:17
  • 1
    And yet, after 6 years your answer help me understand how to install modules in python. Thanks! :) https://stackoverflow.com/questions/44563098/reference-a-library-in-ironpython-using-visual-studio – Davide Vitali Jun 15 '17 at 10:06
2

for understanding where python looks to import your module, you can run following code :

import sys
print(sys.path)

this will show you list of directory names that python searches for your module to import :)

Mehdi Maghrouni
  • 1,529
  • 22
  • 23