Anne questions

• pandas dataframe - filtering gives unexpected error 'unorderable types'
• Python: Nose is not picking up unit test
• concatenating pandas dataframes - all objects passed were None
• Pandas dataframe from series of series
• python: replace zeros by previous nonzero value
• Pandas: remove leading and trailing zero values from series
• pandas read_csv: ignore trailing lines with empty data
• Pandas dataframe: Check if data is monotonically decreasing
• pandas series: change order of index
• pandas: convert datetime to end-of-month

Anne answers