Flask：第二次调用时，@ app.route中的代码失败（永远运行）

Question

I have some Python metapy code being executed inside a Flask route which runs perfectly fine when the route is called the first time (ie a user submits a form after startup of the application) but it doesnt terminate when it runs a second time (ie the form is submitted a second time after application startup).

Precisely:

@app.route('/search', methods=['POST'])
def searchPageResults():
    form = SearchForm(request.form)
    import metapy
    idx = metapy.index.make_inverted_index(os.path.abspath("search/config.toml"))
    ranker = metapy.index.OkapiBM25()
    query = metapy.index.Document()
    query.content("auto")
    for result in ranker.score(idx, query):
         print(result)
    return render_template('SearchPage.html', form=form)

The code snippet inside the method runs fine if I run it outside Flask (no matter how many times I call it). Only inside the method decorated with @app.route(...) it seems to only run once. To be specific: the ranker.score(...) function is the one running forever. Since the code runs fine outside flask, I think there is something Flask specific happening in the background I don't understand.

What I tried so far (but didn't help):

• When I have the "import metapy" statement at the top of the file, then even the first call to ranker.score(...) runs forever.
• I ensured that "import metapy" and the initialization of "idx" and "ranker" only run once by putting the search functionality inside an own Class which is instantiated at Flask server startup. However, also then the code won't run even at the first call of the route.

Is there something Flask specific explaining this behaviour?

----Update: additional info----- config.toml

index = "idx"
corpus = "line.toml"
dataset = "data"
prefix = "."
stop-words = "search/german-stopwords.txt"
start-exceptions = "search/sentence-start-exceptions.txt"
end-exceptions = "search/sentence-end-exceptions.txt"
function-words = "search/function-words.txt"
punctuation = "search/sentence-punctuation.txt"

[[analyzers]]
method = "ngram-word"
ngram = 1
filter = [{type = "icu-tokenizer"}, {type = "lowercase"}]

As said, the behaviour only occurs after the second call of this Flask route. Locally everything works fine (with exact same dataset and config.toml)

Update: same behaviour in MetaPy Flask demo app I have the same behaviour in the MetaPy demo app: https://github.com/meta-toolkit/metapy-demos . (Only difference is that I needed to take some newer versions as specified in the requirements.txt for some packages due to availability).

Answer 1

Solved. There was a problem with the Flask integrated Webserver. Once deployed to another webserver, the problem was solved.