old_contents: # SymPy symbols to exclude.
  exclude  = ('C', 'O', 'S', 'N', 'E', 'E1', 'Q', 'beta', 'gamma', 'zeta')
  
  # Aliases for SymPy symbols
  aliases = {'delta': 'DiracDelta', 'step': 'Heaviside', 'u': 'Heaviside',
             'j': 'I'}
  
  # String replacements when printing as LaTeX.  For example, SymPy uses
  # theta for Heaviside's step.
  latex_string_map = {r'\theta\left': r'u\left'}
  
  import sympy as sym
  print_expr_map = {sym.I: 'j'}
  
  # Hack to pretty print i as j
  junicode = '\u2149'
  from sympy.printing.pretty.pretty_symbology import atoms_table
  atoms_table['ImaginaryUnit'] = junicode
  
  # Words to format in Roman font for LaTeX expressions. 
  words = ('in', 'out', 'ref', 'rms', 'load', 'source', 'avg',
           'mean', 'peak', 'pk', 'pk-pk', 'pp', 'min', 'max', 'src', 'bat',
           'cc', 'ee', 'dd', 'ss', 'ih', 'il', 'oh', 'ol',
           'typ', 'pkg', 'comp', 'step', 'heaviside', 'diracdelta',
           'alpha', 'beta', 'gamma', 'delta', 'eta', 'zeta', 'theta',
           'iota', 'kappa', 'mu', 'nu', 'omicron', 'pi', 'rho', 'sigma', 'tau',
           'upsilon', 'omega')
  
  
new_contents: # SymPy symbols to exclude.
  exclude  = ('I', 'C', 'O', 'S', 'N', 'E', 'E1', 'Q', 'beta', 'gamma', 'zeta')
  
  # Aliases for SymPy symbols
  aliases = {'delta': 'DiracDelta', 'step': 'Heaviside', 'u': 'Heaviside',
             'j': 'I'}
  
  # String replacements when printing as LaTeX.  For example, SymPy uses
  # theta for Heaviside's step.
  latex_string_map = {r'\theta\left': r'u\left'}
  
  import sympy as sym
  print_expr_map = {sym.I: 'j'}
  
  # Hack to pretty print i as j
  junicode = '\u2149'
  from sympy.printing.pretty.pretty_symbology import atoms_table
  atoms_table['ImaginaryUnit'] = junicode
  
  # Words to format in Roman font for LaTeX expressions. 
  words = ('in', 'out', 'ref', 'rms', 'load', 'source', 'avg',
           'mean', 'peak', 'pk', 'pk-pk', 'pp', 'min', 'max', 'src', 'bat',
           'cc', 'ee', 'dd', 'ss', 'ih', 'il', 'oh', 'ol',
           'typ', 'pkg', 'comp', 'step', 'heaviside', 'diracdelta',
           'alpha', 'beta', 'gamma', 'delta', 'eta', 'zeta', 'theta',
           'iota', 'kappa', 'mu', 'nu', 'omicron', 'pi', 'rho', 'sigma', 'tau',
           'upsilon', 'omega')
  
  
subject: Remove I as symbol for imaginary unit