cm-full.py

from pandas import DataFrame
# import the required library to open HDF file
from pandas import HDFStore

# File that stores the dataframe
filename = 'data.h5'
# Creating a dataframe
df = DataFrame(np.random.randn(5,3), columns=['A', 'B', 'C',])

class OpenHDFS():
    """
    Context Manager class to open / create a HDFS / h5 file
    """

    def __init__(self, filename):
        """
        The initialization function, takes the filename
        e.g., "data.h5"
        """
        self.filename = filename

    def __enter__(self):
        """
        Enter the runtime context related to OpenHDFS object
        Opens / creates a HDFS file and returns it.
        """
        self.open_file = HDFStore(self.filename)
        return self.open_file

    def __exit__(self, *args):
        """
        Exit the runtime context related to OpenHDFS object
        Makes sure the file gets closed
        """
        self.open_file.close()        

# Using our context manager
with OpenHDFS(filename) as store:
    store.put('d1', df)