Defaults for bcolz operation

You can tailor the behaviour of bcolz by changing the values of certain some special top level variables whose defaults are listed here. You can change these values in two ways:

  • In your program: the changes will be temporary. For example:

    bcolz.defaults.eval_out_flavor = "numpy"
  • Manually modify the module of the bcolz package: the changes will be persistent. For example, replace:

    defaults.eval_out_flavor = "carray"


    defaults.eval_out_flavor = "numpy"

List of default values


The flavor for the output object in eval(). It can be ‘carray’ or ‘numpy’. Default is ‘carray’.


The virtual machine to be used in computations (via eval()). It can be ‘python’ or ‘numexpr’. Default is ‘numexpr’, if installed. If not, then the default is ‘python’.


The defaults for parameters used in compression (dict). The default is {‘clevel’: 5, ‘shuffle’: True, ‘cname’: ‘blosclz’}.

See Also: