Hey Mikey, let's break down why your script works in PyCharm/IDLE but fails in command line and Java calls, then fix this step by step.

Root Cause of the Syntax Error #

The SyntaxError on the f-string line (f'{frame_folder}/*.jpg') gives away the core issue: the Python version running in your Windows command line doesn’t support f-strings. F-strings were introduced in Python 3.6, so if your system’s default python command points to Python 3.5 or earlier (or even Python 2.x), it’ll throw this error. PyCharm and IDLE use the newer Python interpreter you configured for your project, which is why they work without issues.

Verify Your Command Line Python Version #

Open a Windows command prompt and run:

python --version

If the output is anything older than 3.6, that’s exactly the problem. You can also check python3 --version if you have multiple Python installations.

Solutions to Fix the Issue #

You have two straightforward options here:

Option 1: Make the Script Compatible with Older Python Versions #

Replace the f-string with syntax that works in Python 3.5 and below. Two easy alternatives:

• Use str.format():

  frames = [Image.open(image) for image in glob.glob('{0}/*.jpg'.format(frame_folder))]
  

• Or use string concatenation:

  frames = [Image.open(image) for image in glob.glob(frame_folder + '/*.jpg')]
  

This will let the script run on any Python 2.7+ or 3.x version.

Option 2: Use the Correct Python Version in Command Line & Java #

If you want to keep using f-strings, you need to explicitly call the newer Python interpreter instead of relying on the system default.

For Command Line Testing

Instead of just python genGif.py, use the full path to your 3.6+ Python executable. For example:

C:\Python39\python.exe genGif.py

(Replace the path with the actual location of your newer Python install.)

For Java Call

Your current Java code uses start cmd.exe /k, which opens a separate window and makes debugging hard. Let’s rewrite it with ProcessBuilder (more reliable than Runtime.exec) and specify the correct Python path:

try {
    // Replace with the full path to your Python 3.6+ executable
    String pythonExecutable = "C:\\Python39\\python.exe";
    String scriptPath = "C:\\Users\\user\\PycharmProjects\\rightProgressGifGen\\genGif.py";
    String workingDir = "C:\\Users\\user\\PycharmProjects\\rightProgressGifGen\\";

    // Set up the process builder
    ProcessBuilder processBuilder = new ProcessBuilder(pythonExecutable, scriptPath);
    processBuilder.directory(new File(workingDir)); // Set the script's working directory

    // Redirect error stream to output stream to capture all logs
    processBuilder.redirectErrorStream(true);
    Process process = processBuilder.start();

    // Read the script's output for debugging
    BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
    String line;
    while ((line = reader.readLine()) != null) {
        System.out.println("Script output: " + line);
    }

    // Wait for the script to finish and check exit code
    int exitCode = process.waitFor();
    if (exitCode == 0) {
        // Script ran successfully
        updateProgressRightGif();
    } else {
        System.out.println("Script failed with exit code: " + exitCode);
        // Handle failure case if needed
    }
} catch (Exception e) {
    updateGlobalTime();
    System.out.println("Error running Python script: " + e);
    tweet("Exception running emailTest(). Our time is " + globalHours + ":" + globalMinutes + ":" + globalSeconds);
}

This approach lets you:

• Ensure you’re using the correct Python version every time
• Capture the script’s output/errors for easier debugging
• Wait for the script to complete before running updateProgressRightGif()

Final Checks #

After making these changes:

1. Test the script in command line with the fixed command/script to confirm it works.
2. Run the updated Java code and verify it executes the script successfully.

内容的提问来源于stack exchange，提问作者Mikey