在ROS下安装GPS驱动 nmea_navsat_driver遇到的问题

  File "/home/qrg/catkin_ws/src/nmea_navsat_driver/scripts/nmea_serial_driver", line 35, in 
    import libnmea_navsat_driver.nodes.nmea_serial_driver
  File "/home/qrg/catkin_ws/src/nmea_navsat_driver/src/libnmea_navsat_driver/nodes/nmea_serial_driver.py", line 40, in 
    from libnmea_navsat_driver.driver import RosNMEADriver
  File "/home/qrg/catkin_ws/src/nmea_navsat_driver/src/libnmea_navsat_driver/driver.py", line 41, in 
    from tf.transformations import quaternion_from_euler
  File "/opt/ros/melodic/lib/python2.7/dist-packages/tf/__init__.py", line 30, in 
    from tf2_ros import TransformException as Exception, ConnectivityException, LookupException, ExtrapolationException
  File "/opt/ros/melodic/lib/python2.7/dist-packages/tf2_ros/__init__.py", line 38, in 
    from tf2_py import *
  File "/opt/ros/melodic/lib/python2.7/dist-packages/tf2_py/__init__.py", line 38, in 
    from ._tf2 import *
ImportError: dynamic module does not define module export function (PyInit__tf2)

在ros官网上专门有对这个问题的讨论，一致性的观点是这个问题是由于系统中的python版本混乱导致了。但是查看系统的python版本是python2.7，可能由于系统中存在多了python版本，导致rosrun在运行的时候调用了python导致出错。

将nmea_serial_driver的python 改为2.7版本就不会报错了

#! /usr/bin/env python2.7

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import libnmea_navsat_driver.nodes.nmea_serial_driver


libnmea_navsat_driver.nodes.nmea_serial_driver.main()