data-science — FixDevsLatest fixes and solutions for data-science errors on FixDevs.https://fixdevs.com/enThu, 09 Apr 2026 00:00:00 GMTFix: Jupyter Notebook Not Working — Kernel Dead, Module Not Found, and Widget Errorshttps://fixdevs.com/blog/jupyter-not-working/https://fixdevs.com/blog/jupyter-not-working/How to fix Jupyter errors — kernel fails to start or dies, ModuleNotFoundError despite pip install, matplotlib plots not showing, ipywidgets not rendering in JupyterLab, port already in use, and jupyter command not found.Thu, 09 Apr 2026 00:00:00 GMTpythonjupyterjupyterlabdata-sciencemachine-learningdebuggingFixDevsFix: LightGBM Not Working — Installation Errors, Categorical Features, and Training Issueshttps://fixdevs.com/blog/lightgbm-not-working/https://fixdevs.com/blog/lightgbm-not-working/How to fix LightGBM errors — ImportError libomp libgomp not found, do not support special JSON characters in feature name, categorical feature index out of range, num_leaves vs max_depth overfitting, early stopping callback changes, and GPU build errors.Thu, 09 Apr 2026 00:00:00 GMTpythonlightgbmmachine-learninggradient-boostingdata-sciencedebuggingFixDevsFix: Matplotlib Not Working — Plots Not Showing, Blank Output, and Figure Layout Problemshttps://fixdevs.com/blog/matplotlib-not-working/https://fixdevs.com/blog/matplotlib-not-working/How to fix Matplotlib errors — plot not displaying, blank figure, RuntimeError main thread not in main loop, tight_layout UserWarning, overlapping subplots, savefig saving blank image, backend errors, and figure/axes confusion.Thu, 09 Apr 2026 00:00:00 GMTpythonmatplotlibdata-visualizationdata-scienceplottingdebuggingFixDevsFix: NumPy Not Working — Broadcasting Error, dtype Mismatch, and Array Shape Problemshttps://fixdevs.com/blog/numpy-not-working/https://fixdevs.com/blog/numpy-not-working/How to fix NumPy errors — ValueError operands could not be broadcast together, setting an array element with a sequence, integer overflow, axis confusion, view vs copy bugs, NaN handling, and NumPy 1.24+ removed type aliases.Thu, 09 Apr 2026 00:00:00 GMTpythonnumpydata-sciencemachine-learningdebuggingFixDevsFix: Polars Not Working — AttributeError, InvalidOperationError, and ShapeErrorhttps://fixdevs.com/blog/polars-not-working/https://fixdevs.com/blog/polars-not-working/How to fix Polars errors — AttributeError groupby not found, InvalidOperationError from Python lambdas, ShapeError broadcasting mismatch, lazy vs eager collect confusion, type casting failures, and ColumnNotFoundError in with_columns.Thu, 09 Apr 2026 00:00:00 GMTpythonpolarsdataframedata-sciencedebuggingFixDevsFix: scikit-learn Not Working — NotFittedError, NaN Input, Pipeline, and ConvergenceWarninghttps://fixdevs.com/blog/sklearn-not-working/https://fixdevs.com/blog/sklearn-not-working/How to fix scikit-learn errors — NotFittedError call fit before predict, ValueError Input contains NaN, could not convert string to float, Pipeline ColumnTransformer mistakes, cross-validation leakage, n_jobs hanging on Windows, and ConvergenceWarning.Thu, 09 Apr 2026 00:00:00 GMTpythonscikit-learnmachine-learningsklearndata-sciencedebuggingFixDevsFix: Streamlit Not Working — Session State, Cache, and Rerun Problemshttps://fixdevs.com/blog/streamlit-not-working/https://fixdevs.com/blog/streamlit-not-working/How to fix Streamlit errors — session state KeyError state not persisting, @st.cache deprecated migrate to cache_data cache_resource, file upload resetting, slow app loading on every interaction, secrets not loading, and widget rerun loops.Thu, 09 Apr 2026 00:00:00 GMTpythonstreamlitdata-sciencemachine-learningweb-appdebuggingFixDevsFix: XGBoost Not Working — Feature Name Mismatch, GPU Errors, and Early Stopping Changeshttps://fixdevs.com/blog/xgboost-not-working/https://fixdevs.com/blog/xgboost-not-working/How to fix XGBoost errors — feature names mismatch, XGBoostError GPU training fails, use_label_encoder deprecated, eval_metric warning, early stopping moved to callback, ValueError for DMatrix, and sklearn API confusion.Thu, 09 Apr 2026 00:00:00 GMTpythonxgboostmachine-learninggradient-boostingdata-sciencedebuggingFixDevsFix: pandas SettingWithCopyWarning — A value is trying to be set on a copyhttps://fixdevs.com/blog/pandas-settingwithcopywarning-fix/https://fixdevs.com/blog/pandas-settingwithcopywarning-fix/How to fix pandas SettingWithCopyWarning — understanding chained indexing, using .loc correctly, Copy-on-Write in pandas 2.x, and when the warning indicates a real bug vs a false alarm.Fri, 20 Mar 2026 00:00:00 GMTpythonpandasdebuggingdata-sciencebackendFixDevsFix: pandas merge() Key Error and Duplicate Columns (_x, _y)https://fixdevs.com/blog/pandas-merge-key-error/https://fixdevs.com/blog/pandas-merge-key-error/How to fix pandas merge and join errors — KeyError on merge key, duplicate _x/_y columns, unexpected row counts, suffixes, and how to validate merge results.Thu, 19 Mar 2026 00:00:00 GMTpythonpandasdebuggingdata-scienceFixDevs