TODO.rst

TODO

• Add coverage and tox and integrate with travis-CL
• Add to pivot_table method

2013-07-24

• We need to implement the pivot table method
• Can we bypass the ValuesListQuerySet and numpy_fromrecords and just use the DatatFrame.from_records with the tuple of sql records

2013-07-19

We thinking of implenenting the following API

• to_dataframe - the core method which returns a dataframe based on the columns that you specify you can also set the index column

  Arguments

  cols: the model fields to utilise in creating the frame. to span a relationship, just use the field name of related fields across models, separated by double underscores,

  index: the model field name to use for the index

  coerce_float: The returned columns (except the index) will be floats. This may be required if the queryset returns lots of null values

• to_timeseries - A convenience method to create a pandas time series from a queryset

  Arguments

  freq: A string representing the pandas frequency or date offset

  storage: specify if your queryset uses the wide or long format for data.

  wide format

  ::

  date           gdp     inflation     wages
  
  2010-01-01   204966         2.0       100.7
  
  2010-02-02   204704          2.4       100.4
  
  2010-03-01   205966          2.5       100.5
  

  long or stacked format

  date        series_mame    value
  
  2010-01-01       gdp        204699
  
  2010-01-01       inflation   2.0
  
  2010-01-01       wages       100.7
  
  2010-02-01       gdp        204704
  
  2010-02-01       inflation   2.4
  
  2010-03-01       wages       100.4
  
  2010-02-01       gdp        205966
  
  2010-02-01       inflation   2.5
  
  2010-03-01       wages       100.5
  

  pivot_column: This is required once the you specify long for the storage_fmt. This could either be a list or string identifying the column name or combination of columns that contain the ‘pivot’ identifying column. If your pivot_column is a single column then the unique values in this column become new time series columns. If you sepecify a list of columns then the values in these columns are concatenated (using the '-' as a seperator and these values are used for the new timeseries columns

  values: Also required if you utilize the long storage the values column name is use for populating new frame’s values

  fill_na: Fill in the missing values using the specifies method methods {'backfill, 'bill', 'pad', 'ffill'}

• to_pivot_table - A convenience method to create a pivot table from the queryset

  values: column to aggregate

  rows: the list of column names to group on

  cols: list of column names to group on

  aggfunc: the function to uses in calculate the group aggregate

  fill_value: the value to replace missing values with

  margin: boolean defalut False. Calculate subtotals/grand totals

  dropna: Do not include columns whoes entries are all NaN