Python Pyserial Windows No Port Found

问题

I have just tried to connect to usb mobile to send sms through it using AT commands. But when i use pyserial to connect to it in a windows os, i get error could not open port, the file specified cannot be found.

>>> import serial
>>> ser = serial.Serial(0)  # open first serial port
>>> print ser.name          # check which port was really used
>>> ser.write("hello")      # write a string
>>> ser.close()  

even if i replace the 0 with any other value, like 0 -10 or 'com0','com1' etc, i still get error file specified not found, port cannot be open.

There is a command listed in pyserial documentation which lists ports or allows you to open a port

python -m serial.tools.miniterm

This command is supposed to list all serial ports. But it shows none.

I have 3 usb ports on my system. What is causing this issue.

回答1:

Pyserial is not guaranteed to detect all ports. This depends on how the device and the OS communicate and if pyserial is designed to pick up on this. For Example, pyserial could not detect a LabJack U3-LV or a EPSOM-POS receipt printer I plugged in in a Win8 session (both could be detected using a linux session).

Try serial.tools.list_ports.comports() and see what it gives you.

You could also look at the pyusb module for usb connections.

Also: I recommend being careful when using numbers for ports, as the mapping may not be "common-sense" logical (i.e. 0 may not map to COM0). Use explicit string names instead.

回答2:

I found the solution myself. Its pretty simple and uses the same code in the question.. I was getting blocked error because there was no modem(nokia phone) in my device manager. although i had plugged in my phone into the usb, there was no nokia pc suite installed. Once you install nokia pc suite and connect your nokia phone, in device manager -> modems your phone will appear. Just check its properties->modem and you will find the com5 or whichever number. Then use that id to connect. If you dont know this, just iterate till you find the right one.

Thanks everyone who tried to help

来源：https://stackoverflow.com/questions/29812640/python-pyserial-windows-no-port-found