How to Fix the f-string Error: Unmatched '(' in yfinance

If you’re using the latest version of the yfinance library (version 0.2.45 as of now), you might encounter the following error:

Traceback (most recent call last):

  File ~/anaconda3/envs/fin/lib/python3.10/site-packages/IPython/core/interactiveshell.py:3577 in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)

  Cell In[1], line 1
    import yfinance as yf

  File ~/anaconda3/envs/fin/lib/python3.10/site-packages/yfinance/__init__.py:30
    from .screener.screener import Screener

  File ~/anaconda3/envs/fin/lib/python3.10/site-packages/yfinance/screener/__init__.py:1
    from .screener import Screener

  File ~/anaconda3/envs/fin/lib/python3.10/site-packages/yfinance/screener/screener.py:101
    logger.error(f"Failed to get screener data for '{self._body.get('query', "query not set")}' reason: {e}")
                                                                              ^
SyntaxError: f-string: unmatched '('

Don’t worry! This error is a known issue with the yfinance 0.2.45 source code, and it’s easy to fix. Below, I’ll explain what causes this error and two simple ways to resolve it.

Why This Happens

The issue occurs in this line of the yfinance source code:

logger.error(f"Failed to get screener data for '{self._body.get('query', "query not set")}' reason: {e}")

The problem lies in the mixing of single and double quotes inside the .get() method. Python tries to process both 'query' and "query not set" within the same string, causing confusion. Since the string started with a single quote, Python expects a matching single quote but encounters a double quote, leading to a syntax error.

Two Simple Fixes

You can fix this issue in one of two ways: either by downgrading to an earlier version of yfinance or by manually correcting the source code. Here’s how:

1. Downgrade to a Previous yfinance Version

If you don’t need the latest features of yfinance 0.2.45, simply downgrade to version 0.2.44 by running this command in your terminal:

pip install --force-reinstall -v "yfinance==0.2.44"

After downgrading, restart your Jupyter notebook, and the issue should be resolved.

2. Manually Edit the Source Code

If you prefer to stick with yfinance 0.2.45 for its new features, you can manually correct the problematic line in the source code.

Follow these steps:

1. Locate the file: yfinance/screener/screener.py.
2. Find the offending line:

logger.error(f"Failed to get screener data for '{self._body.get('query', "query not set")}' reason: {e}")

and change it to

logger.error(f"Failed to get screener data for '{self._body.get('query', 'query not set')}' reason: {e}")

This small change ensures consistent use of single quotes, preventing the syntax error.

Conclusion

This error in yfinance version 0.2.45 is easily fixable, either by downgrading to a previous version or manually editing the source code. Choose the method that works best for your needs, and you’ll be back to analyzing financial data in no time!