[mod] searx.engines.__init__: refactoring

[dalf]

What does this PR do?

See comments

Why is this change important?

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Related issues

[return42]

I think setting the headers to ... ja-JP

searxng/searx/engines/__init__.py

Lines 131 to 134 in 737f5f0

	headers = {
	'User-Agent': gen_useragent(),
	'Accept-Language': 'ja-JP,ja;q=0.8,en-US;q=0.5,en;q=0.3', # bing needs a non-English language
	}

is questionable. It comes from 9b6ffed PR-searx 2602 / there is a detailed description I do not have fully understand right now, but since I have updated my instance, sometimes (rare) I observe japan results in my german queries .

[dalf]

I think setting the headers to ... ja-JP is questionable.

?
This change was made to fix searx/data/engines_languages.json updates nothing more and looking at it works: searx/searx@d9dc337#diff-aea534b290d3bf70e79b052cdcf0d1b5df7cbbe92184e40bbe5b373d5699f188

[return42]

This change was made to fix searx/data/engines_languages.json updates nothing more an

Oops .. my fail .. I have sometims (rare) japan results in my german queries, I thought it could be related to this implementation, but now I see it is totaly unrelated .. forget my comment.

[dalf]

Currently, searx.engines.load_engine() exits the program when:

• there is a missing attribute on an engine
• there is an underscore in the name of the engine

---

looking at

searxng/searx/engines/sqlite.py

Lines 25 to 30 in 8567292

	def init(engine_settings):
	if 'query_str' not in engine_settings:
	raise ValueError('query_str cannot be empty')
	if not engine_settings['query_str'].lower().startswith('select '):
	raise ValueError('only SELECT query is supported')

it can be rewritten:

query_str = None  # instead of query_str = ""

def init(engine_settings):
    if not query_str.lower().startswith('select '):  # here `searx.engines.load_engine()` will copy the value from settings.yml to the variable
        raise ValueError('only SELECT query is supported')

ValueError won't stop the engine.

---

--> I suggest searx.engines.load_engine return None instead of sys.exit(1).

[return42]

@dalf I pushed three commits on top of your branch / except 1c13bee no functional change

If you think this commits have a value just merge them along this PR into master, otherwise drop what is not needed.

[return42]

Thanks! .. lets merge ..

[dalf]

Still one sys.exit(1) here otherwise it is possible to have a syntax error in the engine code (it had happened before).