Bowen Peng questions

• How to use tqdm in the cross validtion when using folds.split(train.values, target.values)
• How to optimize such codes as follows in python?
• Why does `categorical_feature` of lightgbm not work?
• how to sum up a vector of vector int in C++ without loops
• There is no argument given that corresponds to the required formal parameter 'value' of Dictionary<string, string>.Add(string, string) [duplicate]
• how to use np.max for empty numpy array without ValueError: zero-size array to reduction operation maximum which has no identity
• How to set the default figure size and DPI of all plots drawn by `matplotlib.pyplot`
• No module named 'graphviz' in Jupyter Notebook

Bowen Peng answers