Viewing file:  unrepr.py (1.32 KB) -rw-r--r--
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import compiler
def unrepr(s):
"""
Convert a string produced by python's repr() into the
corresponding data structure, without calling eval().
"""
return Builder().build(getObj(s))
def getObj(s):
s="a="+s
return compiler.parse(s).getChildren()[1].getChildren()[0].getChildren()[1]
class UnknownType(Exception):
pass
class Builder:
def build(self, o):
m = getattr(self, 'build_'+o.__class__.__name__, None)
if m is None:
raise UnknownType(o.__class__.__name__)
return m(o)
def build_List(self, o):
return map(self.build, o.getChildren())
def build_Const(self, o):
return o.value
def build_Dict(self, o):
d = {}
i = iter(map(self.build, o.getChildren()))
for el in i:
d[el] = i.next()
return d
def build_Tuple(self, o):
return tuple(self.build_List(o))
def build_Name(self, o):
if o.name == 'None':
return None
raise UnknownType('Name')
def build_Add(self, o):
real, imag = map(self.build_Const, o.getChildren())
try:
real = float(real)
except TypeError:
raise UnknownType('Add')
if not isinstance(imag, complex) or imag.real != 0.0:
raise UnknownType('Add')
return real+imag
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