Recently, I changed from using regular pytable HDFStores to fancy frame_tables. The move was mostly for the better as my HDFStores were big. Of course, my old code modifying the dataframes broke because of this little bit of syntax…
In [1]: import pandas as pd
In [2]: p=pd.HDFStore('/path/to/some/hdfstore.h5')
In [3]: p.DF['latitude'][0]=20
In [4]: p.DF['latitude'][0]
Out[4]: -25.0
In [5]: DF=p.select('DF')
In [6]: DF['latitude'][0]=20
In [7]: DF['latitude'][0]
Out[7]: 20.0
In [8]: p
Out[8]:
File path: /path/to/some/hdfstore.h5
/DF frame_table (typ->appendable,nrows->24165608,ncols->7,indexers->[index],dc->[longitude,latitude,depth_m,abstime])
/PARLOC frame_table (typ->appendable,nrows->17913,ncols->4,indexers->[index])
In [10]: pd.__version__
Out[10]: '0.12.0'
Of course, the annoying part is that line four doesn’t throw an error message!
In category: python