def test_assemble(symops, symops_sec):
"""Test, which checks correctness of function parser.assemble,
which reverses what parser.Parser does"""
for nr, symop in enumerate(symops):
#reverting parsing result
back = parser.assemble(parser.Parser(symop))
assert any([ back == symops[nr], back == symops_sec[nr]])
def invert_symop(symb):
""" 'x,y,z' --> '-x,-y,-z'"""
issymbol = lambda s: re.compile(r"[A-Za-z]+").search(s)
isnumber = lambda s: re.compile(r"[+-]?\d+[./]?(\d+)?").search(s)
iszero = lambda s: re.compile(r"[+-]*0").search(s)
minus = "-"
plus = "+"
parsed_list = parser.Parser(symb)
def invert_symbol(symb):
"""x -> -x"""
if iszero(symb):
return "0"
if issymbol(symb):
return symb
if isnumber(symb):
if minus in symb:
return symb[1:]
if plus in symb:
return "-{}".format(symb[1:])
else:
return "-{}".format(symb)
def invert_line(line):
return map(invert_symbol, line)
return parser.assemble(map(invert_line, parser.Parser(symb)))
