semvec/pypi-packages huggingface dataset:
cdblib 0.5
Read and write cdb ("constant database") files
License: MIT
Keywords: cdb constant database

Overview
        ========
        
        Cdblib contains classes to read and write cdb ("constant database") files.
        
        Cdb files map string keys to string values with very fast record lookups.
        Cdblib also allows for in-memory indexes to enable even faster lookups.
        
        See http://cr.yp.to/cdb.html on D. J. Bernstein's site for the original
        specification.
        
        Installation
        ============
        
        Cdblib requires Python 2.5.
        
        The cdblib package contains a C extension module for speedups, but its use
        is not required and makes no difference to the interfaces exposed (except of
        course for speed).
        
        To install with the C extension module for speed, run::
        
        # python setup.py install
        
        Alternatively, you can simply copy the file cdblib.py to somewhere in your
        PYTHONPATH (but this will not include the speedups from the C extension).
        
        Example Usage
        =============
        
        Create a new CDB (or update an existing one):
        
        >>> from cdblib import CDB, CDBWriter
        >>> wcdb = CDBWriter("presidents.cdb") # Create a new CDB file.
        >>> wcdb["Reagan"] = "1981 - 1988"
        >>> wcdb["Bush"] = "1989 - 1992"
        >>> wcdb["Clinton"] = "1993 - 2000"
        >>> wcdb["Bush"] = "2001 - 2008" # Creates a second record with the key "Bush".
        >>> wcdb["Bush"] # Return the first record with key "Bush".
        '1989 - 1992'
        >>> wcdb.getall("Bush") # Return all records with the key "Bush".
        ['1989 - 1992', '2001 - 2008']
        >>> wcdb["Clinton"]
        '1993 - 2000'
        >>> wcdb.getall("Clinton")
        ['1993 - 2000']
        >>> wcdb["Gore"] # Oops, the CDB doesn't contain the key "Gore".
        Traceback (most recent call last):
        File "<stdin>", line 1, in <module>
        File "cdblib.py", line 135, in __getitem__
        raise KeyError(key)
        KeyError: 'Gore'
        >>> wcdb.get("Gore", "Bush") # Return "Bush" if the key "Gore" doesn't exist.
        'Bush'
        >>> wcdb.close() # Close the CDB file and prevent any more writes.
        
        Open an existing CDB read-only:
        
        >>> rcdb = CDB("presidents.cdb") # Re-open the saved CDB file read-only.
        >>> rcdb["Clinton"]
        '1993 - 2000'
        >>> rcdb.close()
        >>> rcdb = CDB("presidents.cdb", load_index=True) # Load the CDB index into memory for faster lookups.