I am making a private messenger using Flask. This Github code is of interest. Executing flask run on command line, Ubuntu 22.04, as instructed on the "README.md" on Github page, the computer returns the following error:
ImportError: cannot import name 'escape' from 'jinja2' (/home/home/.local/lib/python3.10/site-packages/jinja2/__init__.py)
The "requirements.txt" file installed using "pip3 install -r requirements.txt" is as follows:
Flask_SQLAlchemy==2.4.1
Flask_JWT_Extended==3.24.1
Flask_SocketIO==4.2.1
Flask_RESTful==0.3.8
Flask_Migrate==2.5.3
Flask==1.1.1
Flask_Cors==3.0.8
Werkzeug==0.15.4
SQLAlchemy==1.3.5
Kindly help.
I followed the instructions given here. It did not work.
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The above part was solved on 3rd November, 2023, using the answer below by AKX.
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Following the instructions on README.md, both the flask run and npm run serve now run fine. The database part is confusing on README.md. My attempt and error are as follows:
$ python3
Python 3.10.12 (main, Jun 11 2023, 05:26:28) [GCC 11.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from database import init_db
>>> init_db()
Traceback (most recent call last):
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 2262, in _wrap_pool_connect
return fn()
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 363, in connect
return _ConnectionFairy._checkout(self)
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 760, in _checkout
fairy = _ConnectionRecord.checkout(pool)
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 492, in checkout
rec = pool._do_get()
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/pool/impl.py", line 138, in _do_get
with util.safe_reraise():
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/util/langhelpers.py", line 68, in __exit__
compat.reraise(exc_type, exc_value, exc_tb)
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/util/compat.py", line 154, in reraise
raise value
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/pool/impl.py", line 136, in _do_get
return self._create_connection()
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 308, in _create_connection
return _ConnectionRecord(self)
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 437, in __init__
self.__connect(first_connect_check=True)
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 639, in __connect
connection = pool._invoke_creator(self)
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/engine/strategies.py", line 114, in connect
return dialect.connect(*cargs, **cparams)
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/engine/default.py", line 451, in connect
return self.dbapi.connect(*cargs, **cparams)
File "/home/home/.local/lib/python3.10/site-packages/psycopg2/__init__.py", line 122, in connect
conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
psycopg2.OperationalError: connection to server at "localhost" (127.0.0.1), port 5432 failed: FATAL: password authentication failed for user "postgres"
connection to server at "localhost" (127.0.0.1), port 5432 failed: FATAL: password authentication failed for user "postgres"
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/home/home/Documents/doctor_jha/flask/FlaskChat/api/database.py", line 15, in init_db
Base.metadata.create_all(bind=engine)
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/sql/schema.py", line 4286, in create_all
bind._run_visitor(
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 2032, in _run_visitor
with self._optional_conn_ctx_manager(connection) as conn:
File "/usr/lib/python3.10/contextlib.py", line 135, in __enter__
return next(self.gen)
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 2024, in _optional_conn_ctx_manager
with self._contextual_connect() as conn:
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 2226, in _contextual_connect
self._wrap_pool_connect(self.pool.connect, None),
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 2265, in _wrap_pool_connect
Connection._handle_dbapi_exception_noconnection(
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 1536, in _handle_dbapi_exception_noconnection
util.raise_from_cause(sqlalchemy_exception, exc_info)
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/util/compat.py", line 399, in raise_from_cause
reraise(type(exception), exception, tb=exc_tb, cause=cause)
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/util/compat.py", line 153, in reraise
raise value.with_traceback(tb)
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/engine/base.py", line 2262, in _wrap_pool_connect
return fn()
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 363, in connect
return _ConnectionFairy._checkout(self)
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 760, in _checkout
fairy = _ConnectionRecord.checkout(pool)
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 492, in checkout
rec = pool._do_get()
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/pool/impl.py", line 138, in _do_get
with util.safe_reraise():
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/util/langhelpers.py", line 68, in __exit__
compat.reraise(exc_type, exc_value, exc_tb)
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/util/compat.py", line 154, in reraise
raise value
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/pool/impl.py", line 136, in _do_get
return self._create_connection()
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 308, in _create_connection
return _ConnectionRecord(self)
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 437, in __init__
self.__connect(first_connect_check=True)
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/pool/base.py", line 639, in __connect
connection = pool._invoke_creator(self)
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/engine/strategies.py", line 114, in connect
return dialect.connect(*cargs, **cparams)
File "/home/home/.local/lib/python3.10/site-packages/sqlalchemy/engine/default.py", line 451, in connect
return self.dbapi.connect(*cargs, **cparams)
File "/home/home/.local/lib/python3.10/site-packages/psycopg2/__init__.py", line 122, in connect
conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
sqlalchemy.exc.OperationalError: (psycopg2.OperationalError) connection to server at "localhost" (127.0.0.1), port 5432 failed: FATAL: password authentication failed for user "postgres"
connection to server at "localhost" (127.0.0.1), port 5432 failed: FATAL: password authentication failed for user "postgres"
(Background on this error at: http://sqlalche.me/e/e3q8)
>>>
I followed the instructions here and here, but didn't work.
Kindly help.
That repository does not properly lock transitive dependencies, so you've ended up installing a [too-recent version of Jinja2 that doesn't export escape](https://jinja.palletsprojects.com/en/3.1.x/changes/#version-3-1-0, https://github.com/pallets/jinja/pull/1544).
Install an older version of Jinja, and a compatible version of its dependency MarkupSafe too:
pip install "jinja2<3.0" "markupsafe<2.0"