YS-L questions

YS-L answers

• xgboost watchlist parameter: DMatrix object is not iterable
• How to get every single permutation of all substrings of a string?
• Return all possible combinations of a string when splitted into n strings
• Reshaping a pandas DataFrame into stacked/record/database/long format
• Convert result from groupby on multiple columns to list of dictionaries
• What is the correct way to mix feature sparse matrices with sklearn?
• Creating a dataframe with MultiIndex columns from a dictionary
• Search and filter pandas dataframe with regular expressions
• NUMPY create, fill with random binary data
• TypeError: <lambda>() takes exactly 1 argument (3 given)