CoCalc -- Erros.sagews

Project: Book Sage

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Tratamento de Erros no Sage

link da referência: https://docs.python.org/3/library/exceptions.html#RuntimeError

tg(x)

Error in lines 1-1
Traceback (most recent call last):
  File "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/smc_sagews/sage_server.py", line 957, in execute
    exec compile(block+'\n', '', 'single') in namespace, locals
  File "", line 1, in <module>
NameError: name 'tg' is not defined

k+1

Error in lines 1-1
Traceback (most recent call last):
  File "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/smc_sagews/sage_server.py", line 957, in execute
    exec compile(block+'\n', '', 'single') in namespace, locals
  File "", line 1, in <module>
NameError: name 'k' is not defined

lista=[1,2,3];lista[3]

Error in lines 1-1
Traceback (most recent call last):
  File "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/smc_sagews/sage_server.py", line 957, in execute
    exec compile(block+'\n', '', 'single') in namespace, locals
  File "", line 1, in <module>
IndexError: list index out of range

([5,6,7]).union([2,3,4])

Error in lines 1-1
Traceback (most recent call last):
  File "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/smc_sagews/sage_server.py", line 957, in execute
    exec compile(block+'\n', '', 'single') in namespace, locals
  File "", line 1, in <module>
AttributeError: 'list' object has no attribute 'union'

1/0

Error in lines 1-1
Traceback (most recent call last):
  File "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/smc_sagews/sage_server.py", line 957, in execute
    exec compile(block+'\n', '', 'single') in namespace, locals
  File "", line 1, in <module>
  File "sage/rings/integer.pyx", line 1843, in sage.rings.integer.Integer.__div__ (/projects/sage/sage-7.3/src/build/cythonized/sage/rings/integer.c:12742)
    raise ZeroDivisionError("rational division by zero")
ZeroDivisionError: rational division by zero

[1,2,3)

Error in lines 0-1
Traceback (most recent call last):
  File "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/smc_sagews/sage_server.py", line 957, in execute
    exec compile(block+'\n', '', 'single') in namespace, locals
  File "<string>", line 1
    [Integer(1),Integer(2),Integer(3))
                                     ^
SyntaxError: invalid syntax

for i in range(10):
     if i%2==0:
     print i

Error in lines 1-3
Traceback (most recent call last):
  File "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/smc_sagews/sage_server.py", line 957, in execute
    exec compile(block+'\n', '', 'single') in namespace, locals
  File "<string>", line 3
    print i
        ^
IndentationError: expected an indented block

[1,2]+(1,2)

Error in lines 1-1
Traceback (most recent call last):
  File "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/smc_sagews/sage_server.py", line 957, in execute
    exec compile(block+'\n', '', 'single') in namespace, locals
  File "", line 1, in <module>
TypeError: can only concatenate list (not "tuple") to list

for i in x:
  i=i+1

Error in lines 1-2
Traceback (most recent call last):
  File "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/smc_sagews/sage_server.py", line 957, in execute
    exec compile(block+'\n', '', 'single') in namespace, locals
  File "", line 1, in <module>
TypeError: 'sage.symbolic.expression.Expression' object is not iterable

load('texto.py')

Error in lines 1-1
Traceback (most recent call last):
  File "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/smc_sagews/sage_server.py", line 957, in execute
    exec compile(block+'\n', '', 'single') in namespace, locals
  File "", line 1, in <module>
  File "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/smc_sagews/sage_salvus.py", line 3391, in load
    exec 'salvus.namespace["%s"] = sage.structure.sage_object.load(*__args, **__kwds)'%t in salvus.namespace, {'__args':other_args, '__kwds':kwds}
  File "<string>", line 1, in <module>
  File "sage/structure/sage_object.pyx", line 992, in sage.structure.sage_object.load (/projects/sage/sage-7.3/src/build/cythonized/sage/structure/sage_object.c:11186)
    sage.repl.load.load(filename, globals())
  File "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/sage/repl/load.py", line 263, in load
    raise IOError('did not find file %r to load or attach' % filename)
IOError: did not find file 'texto.py' to load or attach

assume(x>0, x<0)

Error in lines 1-1
Traceback (most recent call last):
  File "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/smc_sagews/sage_server.py", line 957, in execute
    exec compile(block+'\n', '', 'single') in namespace, locals
  File "", line 1, in <module>
  File "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/sage/symbolic/assumptions.py", line 515, in assume
    x.assume()
  File "sage/symbolic/expression.pyx", line 1743, in sage.symbolic.expression.Expression.assume (/projects/sage/sage-7.3/src/build/cythonized/sage/symbolic/expression.cpp:12576)
    raise ValueError("Assumption is %s" % str(s._sage_()[0]))
ValueError: Assumption is inconsistent

20//2.3

Error in lines 1-1
Traceback (most recent call last):
  File "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/smc_sagews/sage_server.py", line 957, in execute
    exec compile(block+'\n', '', 'single') in namespace, locals
  File "", line 1, in <module>
  File "sage/structure/element.pyx", line 1896, in sage.structure.element.RingElement.__floordiv__ (/projects/sage/sage-7.3/src/build/cythonized/sage/structure/element.c:16647)
    return coercion_model.bin_op(self, right, floordiv)
  File "sage/structure/coerce.pyx", line 1043, in sage.structure.coerce.CoercionModel_cache_maps.bin_op (/projects/sage/sage-7.3/src/build/cythonized/sage/structure/coerce.c:8958)
    raise
  File "sage/structure/coerce.pyx", line 1039, in sage.structure.coerce.CoercionModel_cache_maps.bin_op (/projects/sage/sage-7.3/src/build/cythonized/sage/structure/coerce.c:8896)
    return PyObject_CallObject(op, xy)
  File "sage/structure/element.pyx", line 1895, in sage.structure.element.RingElement.__floordiv__ (/projects/sage/sage-7.3/src/build/cythonized/sage/structure/element.c:16622)
    return (<RingElement>self)._floordiv_(right)
  File "sage/structure/element.pyx", line 1908, in sage.structure.element.RingElement._floordiv_ (/projects/sage/sage-7.3/src/build/cythonized/sage/structure/element.c:16756)
    raise TypeError(arith_error_message(self, right, floordiv))
TypeError: unsupported operand parent(s) for '//': 'Real Field with 53 bits of precision' and 'Real Field with 53 bits of precision'

var('4')

Error in lines 1-1
Traceback (most recent call last):
  File "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/smc_sagews/sage_server.py", line 957, in execute
    exec compile(block+'\n', '', 'single') in namespace, locals
  File "", line 1, in <module>
  File "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/smc_sagews/sage_salvus.py", line 2922, in var
    return var0(*args, **kwds)
  File "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/smc_sagews/sage_salvus.py", line 2884, in var0
    v = sage.all.SR.var(name, **kwds)
  File "sage/symbolic/ring.pyx", line 759, in sage.symbolic.ring.SymbolicRing.var (/projects/sage/sage-7.3/src/build/cythonized/sage/symbolic/ring.cpp:9295)
    raise ValueError('The name "'+s+'" is not a valid Python identifier.')
ValueError: The name "4" is not a valid Python identifier.

sage: x=10
sage: for i in x:

Error in lines 2-2
Traceback (most recent call last):
  File "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/smc_sagews/sage_server.py", line 957, in execute
    exec compile(block+'\n', '', 'single') in namespace, locals
  File "<string>", line 1
    for i in x:
              ^
SyntaxError: unexpected EOF while parsing

%md 
 ## ** Tratando Exeções **

Tratando Exeções

%md Imagine que um pesquisador necessite avaliar o inverso multiplicativo de valores contidos em uma certa lista de dados obtida atráves de um processo qualquer que inadivertidamente gerou valores iguais a zero. Naturalmente, o valor zero não possui inverso multiplicativo, portanto, um erro de exceção irá interronper o laço.

dados=srange(-1.2,1,0.4, universe=QQ)+srange(-1,1,0.2, universe=QQ)
for i in dados:
    print i, ' -> ', 1/i

-6/5  ->  -5/6
-4/5  ->  -5/4
-2/5  ->  -5/2
0  -> 

Error in lines 2-3
Traceback (most recent call last):
  File "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/smc_sagews/sage_server.py", line 957, in execute
    exec compile(block+'\n', '', 'single') in namespace, locals
  File "", line 2, in <module>
  File "sage/rings/integer.pyx", line 1849, in sage.rings.integer.Integer.__div__ (/projects/sage/sage-7.3/src/build/cythonized/sage/rings/integer.c:12830)
    raise ZeroDivisionError("rational division by zero")
ZeroDivisionError: rational division by zero

%md A interrupção de uma rotina por erro de exceção pode ser bastante inconviniênte. Por exemplo, imagine que um pesquisador necessite avaliar o inverso multiplicativo de valores contidos em uma certa lista de dados obtida atráves de um processo qualquer que inadivertidamente gerou valores iguais a zero. É natural que o laço $\verb|for|$ a seguir seja interropido  pela exceção $\verb|ZeroDivisionError|$ quando encontra o valor $\verb|i=0|$:

A interrupção de uma rotina por erro de exceção pode ser bastante inconviniênte. Por exemplo, imagine que um pesquisador necessite avaliar o inverso multiplicativo de valores contidos em uma certa lista de dados obtida atráves de um processo qualquer que inadivertidamente gerou valores iguais a zero. É natural que o laço $\verb|for|$ a seguir seja interropido pela exceção $\verb|ZeroDivisionError|$ quando encontra o valor $\verb|i=0|$ :

dados=srange(-1.2,1,0.4, universe=QQ)+srange(0,1,0.3, universe=QQ)
for i in dados:
    print i, ' -> ', 1/i

-6/5  ->  -5/6
-4/5  ->  -5/4
-2/5  ->  -5/2
0  -> 

Error in lines 2-3
Traceback (most recent call last):
  File "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/smc_sagews/sage_server.py", line 957, in execute
    exec compile(block+'\n', '', 'single') in namespace, locals
  File "", line 2, in <module>
  File "sage/rings/integer.pyx", line 1849, in sage.rings.integer.Integer.__div__ (/projects/sage/sage-7.3/src/build/cythonized/sage/rings/integer.c:12830)
    raise ZeroDivisionError("rational division by zero")
ZeroDivisionError: rational division by zero

%md Para evitar interrupções na execução de seus comandos você deve tratar as execeções que podem surgir, isto é,

%md 
Sage possui a estutura $\verb|try...except|$ permite que sua rotina seja executada até o final mesmo com a ocorrência de erros de exceção específicos. A sintaxe sintxe mais simplmes para o tratamento de erros de execeção é a que apresetamos a seguir:

Sage possui a estutura $\verb|try...except|$ permite que sua rotina seja executada até o final mesmo com a ocorrência de erros de exceção específicos. A sintaxe sintxe mais simplmes para o tratamento de erros de execeção é a que apresetamos a seguir:

for i in dados:
  try:
      print i, ' -> ', 1/i
  except ZeroDivisionError:
      print 'divisao por zero'
print 'laço encerrado'

-6/5  ->  -5/6
-4/5  ->  -5/4
-2/5  ->  -5/2
0  ->  divisao por zero
2/5  ->  5/2
4/5  ->  5/4
0  ->  divisao por zero
3/10  ->  10/3
3/5  ->  5/3
9/10  ->  10/9
laço encerrado

var('n')

n

int(1.5)

1

int(e)

2

int('1.0')

Error in lines 1-1
Traceback (most recent call last):
  File "/projects/sage/sage-7.3/local/lib/python2.7/site-packages/smc_sagews/sage_server.py", line 957, in execute
    exec compile(block+'\n', '', 'single') in namespace, locals
  File "", line 1, in <module>
ValueError: invalid literal for int() with base 10: '1.0'