I'm getting error for line 1 not sure what the problem is
Traceback (most recent call last):
File "python", line 1, in <module>
File "<string>", line 1, in <module>
NameError: name 'mars' is not defined
Here's the code:
x = int(input("what is the fourth planet in the solar system: "))
if x == mars:
print ("correct")
else print ("incorrect")
You forgot the quotes around mars just like this 'mars'
Related
With Python 2, creating a Decimal with an invalid string produces a useful error message:
>>> import decimal
>>> decimal.Decimal('spam')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/decimal.py", line 547, in __new__
"Invalid literal for Decimal: %r" % value)
File "/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/decimal.py", line 3872, in _raise_error
raise error(explanation)
decimal.InvalidOperation: Invalid literal for Decimal: 'spam'
While Python 3 produces a not-so-helpful message:
>>> import decimal
>>> decimal.Decimal('spam')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
decimal.InvalidOperation: [<class 'decimal.ConversionSyntax'>]
Is there any way to get a useful message like "Invalid literal for Decimal: 'spam'" from the exception in Python 3?
I'm using Python 2.7.15 and Python 3.7.2, both on darwin.
Addenda:
It looks like Python 2 once had a not-very-helpful message for decimal.InvalidOperation: https://bugs.python.org/issue1770009
This situation looks analogous but most of it goes over my head: https://bugs.python.org/issue21227
You could monkey-patch the decimal module.
import decimal
def safe_decimal(something):
try:
funct_holder(something)
except Exception as e:
new_errror = Exception("Hey silly that's not a decimal, what should I do with this? {}".format(something))
raise new_errror from None
funct_holder = decimal.Decimal
decimal.Decimal = safe_decimal
Then you could use the monkey patched version as so
>>> decimal.Decimal('hello')
Traceback (most recent call last):
File "<input>", line 12, in <module>
File "<input>", line 6, in safe_decimal
Exception: Hey silly that's not a decimal, what should I do with this? hello
This is my code but I am getting an error while compiling in python.
Code
print ("Enter the height :")
feet = int(input("feet:"))
Error
Enter the height :
Traceback (most recent call last):
File "main.py", line 2, in <module>
feet = int(raw_input("feet:"))
NameError: name 'raw_input' is not defined
raw_input is no longer a part of python 3.x
You can use
feet = int(input("Enter height in feet: "))
print(feet)
>>> import pdb
>>> x = [1,2,3,4,5]
>>> y = 6
>>> z = 7
>>> r1 = y+z
>>> r1
13
>>> r2 = x+y
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: can only concatenate list (not "int") to list
>>> pdb.set_trace()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib/python3.6/pdb.py", line 1585, in set_trace
Pdb().set_trace(sys._getframe().f_back)
File "/usr/lib/python3.6/pdb.py", line 156, in __init__
readline.set_completer_delims(' \t\n`##$%^&*()=+[{]}\\|;:\'",<>?')
AttributeError: module 'readline' has no attribute 'set_completer_delims'
>>>
Whats problem? run python3.6 an error occurred
I just try to pdb on Cygwin.
(Note that other lib is okay)
In my case the problem was fixed by installing pyreadline:
pip install pyreadline
Please try it.
More info: https://github.com/winpython/winpython/issues/544
I am using Python 3.3 through the IDLE. While running a code that looks like:
raise KeyError('This is a \n Line break')
it outputs:
Traceback (most recent call last):
File "test.py", line 4, in <module>
raise KeyError('This is a \n Line break')
KeyError: 'This is a \n Line break'
I would like it to output the message with the line break like this:
This is a
Line Break
I have tried to convert it to a string before or using os.linesep but nothing seems to work. Is there any way I can force the message to be correctly shown on the IDLE?
If I raise an Exception (instead of KeyError) then the output is what I want, but I would like to still raise a KeyError if possible.
You problem has nothing to do with IDLE. The behavior you see is all from Python. Running current repository CPython interactively, from a command line, we see the behavior you reported.
Python 3.7.0a2+ (heads/pr_3947:01eae2f721, Oct 22 2017, 14:06:43)
[MSC v.1900 32 bit (Intel)] on win32
>>> raise KeyError('This is a \n Line break')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
KeyError: 'This is a \n Line break'
>>> s = 'This is a \n Line break'
>>> s
'This is a \n Line break'
>>> print(s)
This is a
Line break
>>> raise Exception('This is a \n Line break')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
Exception: This is a
Line break
>>> raise IndexError(s)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
IndexError: This is a
Line break
>>> try:
... raise KeyError('This is a \n Line break')
... except KeyError as e:
... print(e)
'This is a \n Line break'
>>> try:
... raise KeyError('This is a \n Line break')
... except KeyError as e:
... print(e.args[0])
This is a
Line break
I don't know why KeyError acts differently from even IndexError, but printing e.args[0] should work for all exceptions.
EDIT
The reason for the difference is given in this old tracker issue, which quotes a comment in the KeyError source code:
/* If args is a tuple of exactly one item, apply repr to args[0].
This is done so that e.g. the exception raised by {}[''] prints
KeyError: ''
rather than the confusing
KeyError
alone. The downside is that if KeyError is raised with an
explanatory
string, that string will be displayed in quotes. Too bad.
If args is anything else, use the default BaseException__str__().
*/
This section appears in the KeyError_str object definition in Objects/exceptions.c of the Python source code.
I will mention your issue as another manifestation of this difference.
There is a way to get the behavior you want: Simply subclass str and override __repr__:
class KeyErrorMessage(str):
def __repr__(self): return str(self)
msg = KeyErrorMessage('Newline\nin\nkey\nerror')
raise KeyError(msg)
Prints:
Traceback (most recent call last):
...
File "", line 5, in
raise KeyError(msg)
KeyError: Newline
in
key
error
The code :
x=0
def ex():
u= input (': ')
if u =='a':
print ('okay')
x = x + 1
ex()
The error :
Traceback (most recent call last):
File "<pyshell#3>", line 1, in <module>
ex ()
File "<pyshell#2>", line 5, in ex
x = x + 1
UnboundLocalError: local variable 'x' referenced before assignment
This is what I get. I have no idea what's wrong. Thanks in advance