def find(sub=None, disp=False):
    if sub is None:
        result = list(_current_constants.keys())
    else:
        result = [key for key in _current_constants
                  if sub.lower() in key.lower()]

    result.sort()
    if disp:
        for key in result:
            print(key)
        return
    else:
        return result

# Table is lacking some digits for exact values: calculate from definition
Return list of physical_constant keys containing a given string.
dataset/ETHPy150Open scipy/scipy/scipy/constants/codata.py/find