data_plot.py 文件源码

def _which(self, program):
        '''
        Mimics which in the unix shell.

        '''
        def is_exe(fpath):
            return os.path.exists(fpath) and os.access(fpath, os.X_OK)

        fpath, fname = os.path.split(program)
        if fpath:
            if is_exe(program):
                return program
        else:
            for path in os.environ["PATH"].split(os.pathsep):
                exe_file = os.path.join(path, program)
                if is_exe(exe_file):
                    return exe_file

        return None