Open
Description
problem
comparison chaining has wrong source positions in most contexts
>>> cnd = True
>>> a = 1 if 1 in 2 == 3 else 0
Traceback (most recent call last):
File "example.py", line 43, in <module>
a = 1 if 1 in 2 == 3 else 0
^^^^^^^^^^^^^^^^^^^^^^^
TypeError: argument of type 'int' is not iterable This bug requires two things to happen:
- The comparison chain has to contain more than on comparison the type does not matter (
==,in,<=,is,...) - The context has to be something other than an expression
no problem
The following examples work:
only one comparison
Traceback (most recent call last):
File "example.py", line 4, in <module>
if 5<"5":
^^^^^
TypeError: '<' not supported between instances of 'int' and 'str'inside expression
>>> a=False or 4<"5"<6
Traceback (most recent call last):
File "example.py", line 15, in <module>
a=False or 4<"5"<6
^^^^^^^
TypeError: '<' not supported between instances of 'int' and 'str'reason
The problem seems to be the positions in the compiled bytecode:
script:
import dis
def foo():
if 1<2<"no int":
return 1
return 0
for p in dis.get_instructions(foo):
print(p.positions, p.opname,p.argval)output (Python 3.11.0rc2+):
Positions(lineno=4, end_lineno=4, col_offset=0, end_col_offset=0) RESUME 0
Positions(lineno=5, end_lineno=5, col_offset=7, end_col_offset=8) LOAD_CONST 1
Positions(lineno=5, end_lineno=5, col_offset=9, end_col_offset=10) LOAD_CONST 2
Positions(lineno=5, end_lineno=6, col_offset=4, end_col_offset=16) SWAP 2
Positions(lineno=5, end_lineno=6, col_offset=4, end_col_offset=16) COPY 2
Positions(lineno=5, end_lineno=6, col_offset=4, end_col_offset=16) COMPARE_OP < # range of the whole if
Positions(lineno=5, end_lineno=6, col_offset=4, end_col_offset=16) POP_JUMP_FORWARD_IF_FALSE 30
Positions(lineno=5, end_lineno=5, col_offset=11, end_col_offset=19) LOAD_CONST no int
Positions(lineno=5, end_lineno=6, col_offset=4, end_col_offset=16) COMPARE_OP < # range of the whole if
Positions(lineno=5, end_lineno=6, col_offset=4, end_col_offset=16) POP_JUMP_FORWARD_IF_FALSE 38
Positions(lineno=5, end_lineno=6, col_offset=4, end_col_offset=16) JUMP_FORWARD 34
Positions(lineno=5, end_lineno=6, col_offset=4, end_col_offset=16) POP_TOP None
Positions(lineno=5, end_lineno=6, col_offset=4, end_col_offset=16) JUMP_FORWARD 38
Positions(lineno=6, end_lineno=6, col_offset=15, end_col_offset=16) LOAD_CONST 1
Positions(lineno=6, end_lineno=6, col_offset=15, end_col_offset=16) RETURN_VALUE None
Positions(lineno=7, end_lineno=7, col_offset=11, end_col_offset=12) LOAD_CONST 0
Positions(lineno=7, end_lineno=7, col_offset=11, end_col_offset=12) RETURN_VALUE Nonethe generated ast looks fine (snippet):
If(
test=Compare(
left=Constant(
value=1,
lineno=5,
col_offset=7, # correct
end_lineno=5,
end_col_offset=8),
ops=[
Lt(),
Lt()],
comparators=[
Constant(
value=2,
lineno=5,
col_offset=9, # correct
end_lineno=5,
end_col_offset=10),
Constant(
value='no int',
lineno=5,
col_offset=11, # correct
end_lineno=5,
end_col_offset=19)],
lineno=5,
col_offset=7,
end_lineno=5,
end_col_offset=19),
other examples
here is a list of all the problems I found so far:
>>> if 4<"5"<6:
... pass
...
Traceback (most recent call last):
File "example.py", line 20, in <module>
if 4<"5"<6:
TypeError: '<' not supported between instances of 'int' and 'str'
>>> while 4<"5"<6:
... pass
...
Traceback (most recent call last):
File "example.py", line 24, in <module>
while 4<"5"<6:
TypeError: '<' not supported between instances of 'int' and 'str'
>>> assert 4<"5"<6
Traceback (most recent call last):
File "example.py", line 27, in <module>
assert 4<"5"<6
TypeError: '<' not supported between instances of 'int' and 'str'
>>> a=2+(5 if 4<"5"<6 else 3)
Traceback (most recent call last):
File "example.py", line 29, in <module>
a=2+(5 if 4<"5"<6 else 3)
^^^^^^^^^^^^^^^^^^^
TypeError: '<' not supported between instances of 'int' and 'str'
>>> a=[a for a in [1] if 4<"5"<a ]
Traceback (most recent call last):
File "example.py", line 34, in <listcomp>
a=[a for a in [1] if 4<"5"<a ]
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: '<' not supported between instances of 'int' and 'str'
>>> a={a for a in [1] if 4<"5"<a }
Traceback (most recent call last):
File "example.py", line 35, in <setcomp>
a={a for a in [1] if 4<"5"<a }
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: '<' not supported between instances of 'int' and 'str'
>>> a={a:a for a in [1] if 4<"5"<a }
Traceback (most recent call last):
File "example.py", line 36, in <dictcomp>
a={a:a for a in [1] if 4<"5"<a }
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: '<' not supported between instances of 'int' and 'str'
>>> a=list((a for a in [1] if 4<"5"<a ))
Traceback (most recent call last):
File "example.py", line 37, in <genexpr>
a=list((a for a in [1] if 4<"5"<a ))
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: '<' not supported between instances of 'int' and 'str'
>>> cnd = True
>>> a = 1 if 1 in 2 == 3 else 0
Traceback (most recent call last):
File "example.py", line 43, in <module>
a = 1 if 1 in 2 == 3 else 0
^^^^^^^^^^^^^^^^^^^^^^^
TypeError: argument of type 'int' is not iterable
>>> if True and 4<"5"<6:
... pass
...
Traceback (most recent call last):
File "example.py", line 45, in <module>
if True and 4<"5"<6:
TypeError: '<' not supported between instances of 'int' and 'str'expected result
The positions should always match the ast-node range:
>>> a=list((a for a in [1] if 4<"5"<a ))
Traceback (most recent call last):
File "example.py", line 37, in <genexpr>
a=list((a for a in [1] if 4<"5"<a ))
^^^^^^^
TypeError: '<' not supported between instances of 'int' and 'str'or, even better only the failing comparison:
>>> a=list((a for a in [1] if 4<"5"<a ))
Traceback (most recent call last):
File "example.py", line 37, in <genexpr>
a=list((a for a in [1] if 4<"5"<a ))
^^^^^
TypeError: '<' not supported between instances of 'int' and 'str'