Detailed explanation of Python's example of parsing cyber record file

Cyber RT is a high-performance, flexible robot operating system open source from Baidu. Cyber record is a tool used in Cyber RT for recording and playback of data. Here is an example of parsing a cyber record file using Python that uses the cyber_py library (Python binding of Cyber RT) to read the record file and print the message information.

1. Environmental preparation

Make sure the Cyber RT development environment is installed andcyber_pyThe library can be used normally.

2. Sample code

The following is based oncyber_py3The library's Cyber Record file parsing sample code supports reading directories or single files, and automatically filters non-Record files:

import argparse
import os
from cyber_py3 import record
from cyber_py3.record import RecordReader, RecordWriter, RecordMessage
 
def parse_record_file(file_path):
    """
     Parse a single Cyber Record file
     """
    try:
        reader = RecordReader(file_path)
        print(f"\n===== Resolving files: {(file_path)} =====")
        print(f"Total number of messages: {reader.get_messagenumber()}")
        print(f"Start time: {reader.get_starttime()}")
        print(f"End time: {reader.get_endtime()}")
        print(f"Channel list: {reader.get_channellist()}\n")
 
        # traverse all messages        for channel_name, msg, datatype, timestamp in reader.read_messages():
            print(f"[aisle] {channel_name}")
            print(f"  Timestamp: {timestamp}")
            print(f"  Data Type: {datatype}")
            print(f"  Message length: {len(msg)} bytes")
            print("-" * 60)
 
    except Exception as e:
        print(f"Parsing files {file_path} fail: {str(e)}")
 
def parse_record_directory(directory):
    """
     Parses all Cyber Record files in the directory
     """
    if not (directory):
        print(f"mistake: {directory} Not a valid directory")
        return
 
    for filename in (directory):
        file_path = (directory, filename)
        
        # Verify whether it is a legal Record file through the file header        if record.is_valid_record_file(file_path):
            parse_record_file(file_path)
        else:
            print(f"Skip non Record document: {filename}")
 
if __name__ == "__main__":
    parser = (description='Cyber Record File Analysis Tool')
    parser.add_argument('path', type=str, help='File path or directory path')
    args = parser.parse_args()
 
    target_path = 
 
    if (target_path):
        if record.is_valid_record_file(target_path):
            parse_record_file(target_path)
        else:
            print(f"mistake: {target_path} Not valid Cyber Record document")
    elif (target_path):
        parse_record_directory(target_path)
    else:
        print(f"mistake: {target_path} Does not exist")

3. Instructions for use

Running example:

# parse a single filepython parse_record.py /path/to/
 
# parse directorypython parse_record.py /path/to/record_dir/

Functional Features:

Automatically verify file validity (pass file header verification)

Display file meta information: number of messages, time range, channel list

Support parsing message header information (channel, timestamp, data type)

Automatically skip invalid files and non-Record files

4. Key implementation instructions

1. File verification:

Binary validation is performed using the record.is_valid_record_file() method

More reliable than simply checking file extensions

2. Message traversal:

reader.read_messages() generator reads messages one by one

Return tuple: (channel_name, message, data_type, timestamp)

3. Performance optimization:

Parse the message content on demand (the current example only reads meta information)

Supports streaming reading of large files (no full content loading into memory)

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