如何通过Python脚本获取Python版本的build编号？

Nice question! The standard sys and platform modules are great for grabbing Python's core version info, but they don't expose RPM-specific build metadata like the 48 in python-2.7.5-48.el7.x86_64. Fortunately, you can absolutely retrieve this from within Python by executing the RPM command and parsing its output. Here's a reliable approach:

The Approach #

We'll use Python's subprocess module to run an RPM query (with a custom output format to make parsing easier), then extract the build number from the result. This avoids messy string matching on raw rpm -qa output and targets exactly the data we need.

Example Code #

import subprocess

def fetch_python_rpm_build_number():
    try:
        # Run RPM query with structured output to get name, version, and release
        rpm_output = subprocess.run(
            ["rpm", "-qa", "--queryformat", "%{NAME}-%{VERSION}-%{RELEASE}\n"],
            capture_output=True,
            text=True,
            check=True
        )
        
        # Iterate through output lines to find Python packages
        for line in rpm_output.stdout.splitlines():
            # Match main Python packages (adjust if you need specific variants like python-devel)
            if line.startswith("python") or line.startswith("python3"):
                # Split the line into components: e.g., "python-2.7.5-48.el7" → ["python", "2.7.5", "48.el7"]
                package_parts = line.split("-")
                # The release segment contains the build number + distro tag
                release_segment = package_parts[-1]
                # Extract the build number (before the distro dot, e.g., "48" from "48.el7")
                build_number = release_segment.split(".")[0]
                return build_number
        
        # No matching Python package found
        return None
    except subprocess.CalledProcessError:
        # Command failed (likely not an RPM-based system)
        return None
    except IndexError:
        # Parsing failed due to unexpected output format
        return None

# Test the function
build_num = fetch_python_rpm_build_number()
if build_num:
    print(f"Python RPM build number: {build_num}")
else:
    print("Could not retrieve the RPM build number—this may not be an RPM-based system, or the Python package wasn't found.")

Key Notes #

• RPM-Specific: This only works on RPM-based systems like RHEL, CentOS, Fedora, etc. It won't work on Debian/Ubuntu (which use dpkg) or non-Linux systems.
• Precision: Using --queryformat gives us structured output, which is more reliable than piping to grep directly—we avoid matching unrelated packages that include "python" in their name.
• Permissions: Most users can run rpm -qa without root access, so this should work in most environments.

If you need to target a specific Python package (like python-devel instead of the main runtime), just adjust the string check in the loop to match your desired package name.

内容的提问来源于stack exchange，提问作者Vatsal Prakash