# scipy.constants.find

scipy.constants.find(sub=None, disp=False)

  Return list of physical_constant keys containing a given string.

  Parameters:
    sub str

      Sub-string to search keys for. By default, return all keys.

    disp bool

      If True, print the keys that are found and return None. Otherwise, return the list of keys without printing anything.

  Returns:
    keys list or None

      If disp is False, the list of keys is returned. Otherwise, None is returned.

  Examples

      >>> from scipy.constants import find, physical_constants

  Which keys in the `physical_constants` dictionary contain ‘boltzmann’?

      >>> find('boltzmann')
      ['Boltzmann constant',
       'Boltzmann constant in Hz/K',
       'Boltzmann constant in eV/K',
       'Boltzmann constant in inverse meter per kelvin',
       'Stefan-Boltzmann constant']

  Get the constant called ‘Boltzmann constant in Hz/K’:

      >>> physical_constants['Boltzmann constant in Hz/K']
      (20836619120.0, 'Hz K^-1', 0.0)

  Find constants with ‘radius’ in the key:

      >>> find('radius')
      ['Bohr radius',
       'classical electron radius',
       'deuteron rms charge radius',
       'proton rms charge radius']
      >>> physical_constants['classical electron radius']
      (2.8179403262e-15, 'm', 1.3e-24)