This is my attempt so far to trap all exceptions in Jython code. The most difficult thing, I find, is trapping exceptions when you override a method from a Java class: with the "vigil" decorator below (which also tests whether the EDT/Event Despatch Thread status is correct) you can find out the first line where the code is thrown... so you can identify the method itself. But not the line.
Furthermore, tracing stack frames back through Python and Java stacks is completely beyond me. Obviously there seem to be these layers and layers of "proxy" classes, a no doubt inevitable part of Jython mechanics. It'd be great if someone much cleverer than me were to take an interest in this question!
NB this is an example of how to use the "vigil" decorator:
class ColumnCellRenderer( javax.swing.table.DefaultTableCellRenderer ):
#vigil( True ) # means a check is done that the thread is the EDT, as well as intercepting Python Exceptions and Java Throwables...
def getTableCellRendererComponent( self, table, value, isSelected, hasFocus, row, column):
super_comp = self.super__getTableCellRendererComponent( table, value, isSelected, hasFocus, row, column)
super_comp.foreground = java.awt.Color.black
super_comp.font = main_frame_self.m_plain_font
...
... and these are three functions I use in an attempt to trap stuff...
def custom_hook(type_of_e, e, tb ):
"""
Method to catch Python-style BaseExceptions, using the command sys.excepthook = custom_hook.
The first thing this method needs to do in Jython is to determine whether this is a Java
java.lang.Throwable or not. If it is this JThrowable
must be handled by the code which caters for B{uncaught Java Throwables}.
"""
try:
if 'tb' not in locals():
tb = None
logger.error("Python custom_hook called...\ntype of e: %s\ne: %s\ntb: %s" % ( unicode( type_of_e ), unicode( e ),
unicode( tb ) ))
msg = ''.join( traceback.format_exception(type_of_e, e, tb ))
logger.error( "traceback:\n" + msg )
except BaseException, e:
logger.error( "exception in Python custom_hook!:\n%s" % e )
raise e
sys.excepthook = custom_hook
class JavaUncaughtExceptHandler( java.lang.Thread.UncaughtExceptionHandler ):
"""
java.lang.Class to catch any Java Throwables thrown by the app.
"""
def uncaughtException( self, thread, throwable ):
try:
'''
NB getting the Java stack trace like this seems to produce a very different trace
from throwable.printStackTrace()... why?
'''
# we want a single log message
exception_msg = "\n*** uncaught Java Exception being logged in %s:\n" % __file__
baos = java.io.ByteArrayOutputStream()
ps = java.io.PrintStream(baos)
throwable.printStackTrace( ps )
# remove multiple lines from Java stack trace message
java_stack_trace_lines = unicode( baos.toString( "ISO-8859-1" )).splitlines()
java_stack_trace_lines = filter( None, java_stack_trace_lines )
normalised_java_stack_trace = '\n'.join( java_stack_trace_lines )
exception_msg += normalised_java_stack_trace + '\n'
python_traceback_string = traceback.format_exc()
exception_msg += "Python traceback:\n%s" % python_traceback_string
logger.error( exception_msg )
except (BaseException, java.lang.Throwable ), e:
logger.error( "*** exception in Java exception handler:\ntype %s\n%s" % ( type( e ), unicode( e ) ) )
raise e
# NB printStackTrace causes the custom_hook to be invoked... (but doesn't print anything)
java.lang.Thread.setDefaultUncaughtExceptionHandler( JavaUncaughtExceptHandler() )
def vigil( *args ):
"""
Decorator with two functions.
1. to check that a method is being run in the EDT or a non-EDT thread;
2. to catch any Java Throwables which otherwise would not be properly caught and documented: in particular,
with normal Java error-trapping in Jython it seems impossible to determine the line number at which an
Exception was thrown. This at least records the line at which a Java java.lang.Throwable
was thrown.
"""
if len( args ) != 1:
raise Exception( "vigil: wrong number of args (should be 1, value: None/True/False): %s" % str( args ))
req_edt = args[ 0 ]
if req_edt and type( req_edt ) is not bool:
raise Exception( "vigil: edt_status is wrong type: %s, type %s" % ( req_edt, type( req_edt )) )
def real_decorator( function ):
if not hasattr( function, '__call__' ):
raise Exception( "vigil: function %s does not have __call__ attr, type %s"
% ( function, type( function )) )
# NB info about decorator location can't be got when wrapper called, so record it at this point
penultimate_frame = traceback.extract_stack()[ -2 ]
decorator_file = penultimate_frame[ 0 ]
decorator_line_no = penultimate_frame[ 1 ]
def wrapper( *args, **kvargs ):
try:
# TODO is it possible to get the Python and/or Java stack trace at this point?
if req_edt and javax.swing.SwingUtilities.isEventDispatchThread() != req_edt:
logger.error( "*** vigil: wrong EDT value, should be %s\nfile %s, line no %s, function: %s\n" %
( "EDT" if req_edt else "non-EDT", decorator_file, decorator_line_no, function ))
return function( *args, **kvargs )
except ( BaseException, java.lang.Throwable ), e:
''' NB All sorts of problems if a vigil-protected function throws an exception:
1) just raising e means you get a very short stack trace...
2) if you list the stack trace elements here you get a line (seemingly inside the function where the
exception occurred) but often the wrong line!
3) Python/Java stack frames: how the hell does it all work???
4) want a single error message to be logged
'''
msg = "*** exception %s caught by vigil in file %s\nin function starting line %d" % ( e, decorator_file, decorator_line_no )
logger.error( msg )
frame = inspect.currentframe()
# the following doesn't seem to work... why not?
python_stack_trace = traceback.format_stack(frame)
python_stack_string = "Python stack trace:\n"
for el in python_stack_trace[ : -1 ]:
python_stack_string += el
logger.error( python_stack_string )
if isinstance( e, java.lang.Throwable ):
# NB problems with this stack trace: although it appears to show the
# correct Java calling pathway, it seems that the line number of every file and method
# is always shown as being the last line, wherever the exception was actually raised.
# Possibly try and get hold of the actual Pyxxx objects ... (?)
java_stack_trace = e.stackTrace
java_stack_string = "Java stack trace:\n"
for el in java_stack_trace:
java_stack_string += " %s\n" % unicode( el )
logger.error( java_stack_string )
raise e
return wrapper
return real_decorator
PS it is of course possible to top-and-tail every overridden Java method with try ... except... but where's the fun in that? Seriously, even doing that I'm unable to find the line at which the exception is thrown...
Here's an example of a decorator used in the socket module in Jython to map Java exceptions to Python exceptions. I didn't read your vigil decorator too closely since it's doing a lot of work, but I'm putting it here in case it might help:
def raises_java_exception(method_or_function):
"""Maps java socket exceptions to the equivalent python exception.
Also sets _last_error on socket objects so as to support SO_ERROR.
"""
#wraps(method_or_function)
def handle_exception(*args, **kwargs):
is_socket = len(args) > 0 and isinstance(args[0], _realsocket)
try:
try:
return method_or_function(*args, **kwargs)
except java.lang.Exception, jlx:
raise _map_exception(jlx)
except error, e:
if is_socket:
args[0]._last_error = e[0]
raise
else:
if is_socket:
args[0]._last_error = 0
return handle_exception
Mostly what we are seeing here is that we are dispatching on whether it is a Java exception (java.lang.Exception) or not. I suppose this could be generalized to java.lang.Throwable, although it's unclear what can be done in the case of java.lang.Error in any event. Certainly nothing corresponding to socket errors!
The above decorator in turn uses the _map_exception function to unwrap the Java exception. It's quite application specific here as you can see:
def _map_exception(java_exception):
if isinstance(java_exception, NettyChannelException):
java_exception = java_exception.cause # unwrap
if isinstance(java_exception, SSLException) or isinstance(java_exception, CertificateException):
cause = java_exception.cause
if cause:
msg = "%s (%s)" % (java_exception.message, cause)
else:
msg = java_exception.message
py_exception = SSLError(SSL_ERROR_SSL, msg)
else:
mapped_exception = _exception_map.get(java_exception.__class__)
if mapped_exception:
py_exception = mapped_exception(java_exception)
else:
py_exception = error(-1, 'Unmapped exception: %s' % java_exception)
py_exception.java_exception = java_exception
return _add_exception_attrs(py_exception)
There is some clunkiness in the code, and I'm sure room for improvement, but overall it certainly makes any decorated code much easier to follow. Example:
#raises_java_exception
def gethostname():
return str(InetAddress.getLocalHost().getHostName())
Jim Baker's answer is interesting... but what I wanted is sthg comprehensive which documents the maximum possible amount of stack trace info when an exception of any kind is raised. CPython not being multi-thread, its stack trace doesn't have to cope with Runnables. I'm not enough of a Jython/Python expert to know whether you can always get the whole stack in "pure Python" code (i.e. no use of Java classes).
But one of the things I wanted to get was the activity which had led up to the running of a Runnable in Jython. And the activity which had led up to the Runnable having run that Runnable, etc., right back to the very first thread. My solution below, taking inspiration from Jim's answer but also from doublep's comment, creates a new Jython class, TraceableRunnable, which will store the list of stack traces on creation.
When an exception, either Java or Python style, is raised, this logs everything right back to the start of the run (if you systematically use TraceableRunnable instead of Runnable).
Each run() code of a TraceableRunner subclass also has to do this call at some point:
self.record_thread()
... hopefully this is not too irksome an imposition...
(NB in a truly "grown up" implementation you'd want to check that this call had been made... I'm sure that this could be done by some suitably sophisticated Pythonic technique, failing which by unit testing or something. Also you might want to require a call at the very end of the run() code to delete this dictionary entry...)
This is the catching and logging code:
class TraceableRunnable( java.lang.Runnable ):
thread_to_tr_dic = {}
def __init__( self ):
# no need to call super's __init__: Runnable is a Java *interface*
caller_thread = java.lang.Thread.currentThread()
self.frame_stack_list = []
if hasattr( caller_thread, 'frame_stack_list' ):
self.frame_stack_list = copy.deepcopy( caller_thread.frame_stack_list )
self.frame_stack_list.append( traceback.extract_stack() )
def record_thread( self ):
TraceableRunnable.thread_to_tr_dic[ java.lang.Thread.currentThread() ] = self
class EDTException( Exception ):
pass
def vigil( *args ):
"""
Decorator with two functions.
1. to check that a method is being run in the EDT or a non-EDT thread
2. to catch any exceptions
"""
if len( args ) != 1:
raise Exception( "vigil: wrong number of args (should be 1, value: None/True/False): %s" % str( args ))
req_edt = args[ 0 ]
if req_edt and type( req_edt ) is not bool:
raise Exception( "vigil: edt_status is wrong type: %s, type %s" % ( req_edt, type( req_edt )) )
def process_exception( exc, python = True ):
tb_obj = sys.exc_info()[ 2 ]
msg = "Exception thrown message %s\nfamily %s, type: %s\n" % ( str( exc ), "Python" if python else "Java", type( exc ))
msg += "traceback object part:\n"
ex_tb = traceback.extract_tb( tb_obj )
# first is frame in vigil
ex_tb = ex_tb[ 1 : ]
if not ex_tb:
msg += " none\n"
else:
tb_strings = traceback.format_list( ex_tb )
for tb_string in tb_strings:
msg += tb_string
curr_thread = java.lang.Thread.currentThread()
if curr_thread in TraceableRunnable.thread_to_tr_dic:
runnable = TraceableRunnable.thread_to_tr_dic[ curr_thread ]
# duck-typing, obviously... although redundant test, as only TraceableRunnables should be in the dictionary...
if hasattr( runnable, 'frame_stack_list' ):
msg += "\nOLDER STACKS:\n"
for frame_stack in runnable.frame_stack_list:
msg += "\nframe stack id: %d\n" % id( frame_stack )
frame_stack = frame_stack[ : -1 ]
if not frame_stack:
msg += " no frames\n"
else:
# most recent call first: reverse array...
stack_strings = traceback.format_list( reversed( frame_stack ))
for stack_string in stack_strings:
msg += stack_string
logger.error( msg )
def real_decorator( function ):
if not hasattr( function, '__call__' ):
raise Exception( "vigil: function %s does not have __call__ attr, type %s"
% ( function, type( function )) )
# NB info about decorator location can't be got when wrapper called, so record it at this point
penultimate_frame = traceback.extract_stack()[ -2 ]
decorator_file = penultimate_frame[ 0 ]
decorator_line_no = penultimate_frame[ 1 ]
def wrapper( *args, **kvargs ):
try:
if req_edt is not None and javax.swing.SwingUtilities.isEventDispatchThread() != req_edt:
msg = \
"vigil: wrong EDT value, should be %s\nfile %s\nline no %s, function: %s" % \
( "EDT" if req_edt else "non-EDT", decorator_file, decorator_line_no, function )
raise EDTException( msg )
return function( *args, **kvargs )
except BaseException, e:
# we cannot know how calling code will want to deal with an EDTException
if type( e ) is EDTException:
raise e
process_exception( e )
except java.lang.Throwable, t:
process_exception( t, False )
return wrapper
return real_decorator
Would welcome improvements from proper programmers...!
Related
I am having trouble in making things work with a Custom ParallelEnv I wrote by using PettingZoo. I am using SuperSuit's ss.pettingzoo_env_to_vec_env_v1(env) as a wrapper to Vectorize the environment and make it work with Stable-Baseline3 and documented here.
You can find attached a summary of the most relevant part of the code:
from typing import Optional
from gym import spaces
import random
import numpy as np
from pettingzoo import ParallelEnv
from pettingzoo.utils.conversions import parallel_wrapper_fn
import supersuit as ss
from gym.utils import EzPickle, seeding
def env(**kwargs):
env_ = parallel_env(**kwargs)
env_ = ss.pettingzoo_env_to_vec_env_v1(env_)
#env_ = ss.concat_vec_envs_v1(env_, 1)
return env_
petting_zoo = env
class parallel_env(ParallelEnv, EzPickle):
metadata = {'render_modes': ['ansi'], "name": "PlayerEnv-Multi-v0"}
def __init__(self, n_agents: int = 20, new_step_api: bool = True) -> None:
EzPickle.__init__(
self,
n_agents,
new_step_api
)
self._episode_ended = False
self.n_agents = n_agents
self.possible_agents = [
f"player_{idx}" for idx in range(n_agents)]
self.agents = self.possible_agents[:]
self.agent_name_mapping = dict(
zip(self.possible_agents, list(range(len(self.possible_agents))))
)
self.observation_spaces = spaces.Dict(
{agent: spaces.Box(shape=(len(self.agents),),
dtype=np.float64, low=0.0, high=1.0) for agent in self.possible_agents}
)
self.action_spaces = spaces.Dict(
{agent: spaces.Discrete(4) for agent in self.possible_agents}
)
self.current_step = 0
def seed(self, seed=None):
self.np_random, seed = seeding.np_random(seed)
def observation_space(self, agent):
return self.observation_spaces[agent]
def action_space(self, agent):
return self.action_spaces[agent]
def __calculate_observation(self, agent_id: int) -> np.ndarray:
return self.observation_space(agent_id).sample()
def __calculate_observations(self) -> np.ndarray:
observations = {
agent: self.__calculate_observation(
agent_id=agent)
for agent in self.agents
}
return observations
def observe(self, agent):
return self.__calculate_observation(agent_id=agent)
def step(self, actions):
if self._episode_ended:
return self.reset()
observations = self.__calculate_observations()
rewards = random.sample(range(100), self.n_agents)
self.current_step += 1
self._episode_ended = self.current_step >= 100
infos = {agent: {} for agent in self.agents}
dones = {agent: self._episode_ended for agent in self.agents}
rewards = {
self.agents[i]: rewards[i]
for i in range(len(self.agents))
}
if self._episode_ended:
self.agents = {} # To satisfy `set(par_env.agents) == live_agents`
return observations, rewards, dones, infos
def reset(self,
seed: Optional[int] = None,
return_info: bool = False,
options: Optional[dict] = None,):
self.agents = self.possible_agents[:]
self._episode_ended = False
self.current_step = 0
observations = self.__calculate_observations()
return observations
def render(self, mode="human"):
# TODO: IMPLEMENT
print("TO BE IMPLEMENTED")
def close(self):
pass
Unfortunately when I try to test with the following main procedure:
from stable_baselines3 import DQN, PPO
from stable_baselines3.common.env_checker import check_env
from dummy_env import dummy
from pettingzoo.test import parallel_api_test
if __name__ == '__main__':
# Testing the parallel algorithm alone
env_parallel = dummy.parallel_env()
parallel_api_test(env_parallel) # This works!
# Testing the environment with the wrapper
env = dummy.petting_zoo()
# ERROR: AssertionError: The observation returned by the `reset()` method does not match the given observation space
check_env(env)
# Model initialization
model = PPO("MlpPolicy", env, verbose=1)
# ERROR: ValueError: could not broadcast input array from shape (20,20) into shape (20,)
model.learn(total_timesteps=10_000)
I get the following error:
AssertionError: The observation returned by the `reset()` method does not match the given observation space
If I skip check_env() I get the following one:
ValueError: could not broadcast input array from shape (20,20) into shape (20,)
It seems like that ss.pettingzoo_env_to_vec_env_v1(env) is capable of splitting the parallel environment in multiple vectorized ones, but not for the reset() function.
Does anyone know how to fix this problem?
Plese find the Github Repository to reproduce the problem.
You should double check the reset() function in PettingZoo. It will return None instead of an observation like GYM
Thanks to discussion I had in the issue section of the SuperSuit repository, I am able to post the solution to the problem. Thanks to jjshoots!
First of all it is necessary to have the latest SuperSuit version. In order to get that I needed to install Stable-Baseline3 using the instructions here to make it work with gym 0.24+.
After that, taking the code in the question as example, it is necessary to substitute
def env(**kwargs):
env_ = parallel_env(**kwargs)
env_ = ss.pettingzoo_env_to_vec_env_v1(env_)
#env_ = ss.concat_vec_envs_v1(env_, 1)
return env_
with
def env(**kwargs):
env_ = parallel_env(**kwargs)
env_ = ss.pettingzoo_env_to_vec_env_v1(env_)
env_ = ss.concat_vec_envs_v1(env_, 1, base_class="stable_baselines3")
return env_
The outcomes are:
Outcome 1: leaving the line with check_env(env) I got an error AssertionError: Your environment must inherit from the gym.Env class cf https://github.com/openai/gym/blob/master/gym/core.py
Outcome 2: removing the line with check_env(env), the agent starts training successfully!
In the end, I think that the argument base_class="stable_baselines3" made the difference.
Only the small problem on check_env remains to be reported, but I think it can be considered as trivial if the training works.
need your kind help!
I have defined a new Exception called 'UnderAge' (just checking if a person is under an age limit).
The strange thing is that when i use 'raise UnderAge as e....' it does not work under the 'try' segment.
only the exception is working.
Here is the code :
class UnderAge(Exception):
def __init__(self, name, age):
self._name = name
self._age = age
def __str__(self):
return "the age %s is under 18 yo" % self._age
def get_age(self):
return self._age
def send_invitation(name, age):
try:
if int(age) < 18:
raise UnderAge(name, age)
else:
print("You should send an invitation to " + name)
except UnderAge as e:
print("Age must be above 18 but now age is %s." % e.get_age())
def main():
send_invitation("miri", 16)
if __name__ == "__main__":
main()
-----When running it i only get :
C:\Python\Python38-32\python.exe "C:/Users/mikie/Documents/Pyton Programs/Next.py Course/Targil_3.3.2a.py"
Age must be above 18 but now age is 16.
Process finished with exit code 0
----- i should see also an output indicating the UnderAge and its relevant str which i have changed.
Please help me guys:-)
thanks,
Mike
false alarm - this is a normal behaviour of the raise.
It should pop the customized exception only if there is no exception defined in the code after the 'try'.
Also, the string which overrides the__str__ can be called by e.str.
I have this sqlite3.register_converter function :
def str_to_dict(s: ByteString) -> Dict:
if s and isinstance(s, ByteString):
s = s.decode('UTF-8').replace("'", '"')
return json.loads(s)
raise TypeError(f'value : "{s}" should be a byte string')
which returns this exception text :
File "/usr/lib64/python3.7/json/decoder.py", line 355, in raw_decode
raise JSONDecodeError("Expecting value", s, err.value) from None
json.decoder.JSONDecodeError: Expecting value: line 1 column 30 (char 29)
when encounter with this string :
s = b"{'foo': {'bar': [('for', 'grid')]}}"
It seems that the issue comes from the nested list/tuple/dictionary but what I don't understand is that in the sqlite shell, the value is correctly returned with a select command :
select * from table;
whereas the same command issued from a python script returned the exception above :
class SqliteDb:
def __init__(self, file_path: str = '/tmp/database.db'):
self.file_path = file_path
self._db = sqlite3.connect(self.file_path, detect_types=sqlite3.PARSE_DECLTYPES | sqlite3.PARSE_COLNAMES)
if self._db:
self._cursor = self._db.cursor()
else:
raise ValueError
# register data types converters and adapters
sqlite3.register_adapter(Dict, dict_to_str)
sqlite3.register_converter('Dict', str_to_dict)
sqlite3.register_adapter(List, list_to_str)
sqlite3.register_converter('List', str_to_list)
def __del__(self):
self._cursor.close()
self._db.close()
def select_from(self, table_name: str):
with self._db:
query = f'SELECT * FROM {table_name}'
self._cursor.execute(query)
if __name__ == '__main__':
try:
sq = SqliteDb()
selection_item = sq.select_from("table")[0]
print(f'selection_item : {selection_item}')
except KeyboardInterrupt:
print('\n')
sys.exit(0)
s, the value is already saved in database with no issue. Only the selection causes this issue.
So, anybody has a clue why ?
Your input is really a Python dict literal, and contains structures such as the tuple ('for', 'grid') that cannot be directly parsed as JSON even after you replace single quotes with double quotes.
You can use ast.literal_eval instead to parse the input:
from ast import literal_eval
def str_to_dict(s: ByteString) -> Dict:
return literal_eval(s.decode())
So i have a program which will encrypt a string using AES and generate cipher which in bytes[].
I wish to store this cipher as it is in mysql database.
I found we could use VARBINARY data type in mysql to do so.
In what ways we could achieve so.
Here is my try to do so :
import ast
import mysql.connector
from Crypto.Cipher import AES
from Crypto.Random import get_random_bytes
def encrypt(key, msg):
iv = get_random_bytes(16)
cipher = AES.new(key, AES.MODE_CFB, iv)
ciphertext = cipher.encrypt(msg) # Use the right method here
db = iv + ciphertext
print(db)
cursor.executemany(sql_para_query,db)
print(cursor.fetchone())
connection.commit()
return iv + ciphertext
def decrypt(key, ciphertext):
iv = ciphertext[:16]
ciphertext = ciphertext[16:]
cipher = AES.new(key, AES.MODE_CFB, iv)
msg = cipher.decrypt(ciphertext)
return msg.decode("utf-8")
if __name__ == "__main__":
connection = mysql.connector.connect(host = "localhost", database = "test_db", user = "sann", password = "userpass",use_pure=True)
cursor = connection.cursor(prepared = True)
sql_para_query = """insert into test1 values(UNHEX(%s)) """
ed = input("(e)ncrypt or (d)ecrypt: ")
key = str(1234567899876543)
if ed == "e":
msg = input("message: ")
s= encrypt(key, msg)
print("Encrypted message: ", s)
file = open("e_tmp","wb+")
file.write(s)
print(type(s))
elif ed == "d":
#smsg = input("encrypted message: ")
#file = open("e_tmp","rb")
#smsg = file.read()
#print(type(smsg))
sql_para_query = """select * from test1"""
cursor.execute(sql_para_query)
row = cursor.fetchone()
print(row)
#smsg = str(smsg)
#msg = ast.literal_eval(smsg)
#print(msg)
#print(type(msg))
#s=decrypt(key, msg)
#print("Decrypted message: ", s)
#print(type(s))
Error I'm getting :
Traceback (most recent call last): File
"/home/mr_pool/.local/lib/python3.6/site-packages/mysql/connector/cursor.py",
line 1233, in executemany
self.execute(operation, params) File "/home/mr_pool/.local/lib/python3.6/site-packages/mysql/connector/cursor.py",
line 1207, in execute
elif len(self._prepared['parameters']) != len(params): TypeError: object of type 'int' has no len()
During handling of the above exception, another exception occurred:
Traceback (most recent call last): File "tmp1.py", line 36, in
s= encrypt(key, msg) File "tmp1.py", line 14, in encrypt
cursor.executemany(sql_para_query,db) File "/home/mr_pool/.local/lib/python3.6/site-packages/mysql/connector/cursor.py",
line 1239, in executemany
"Failed executing the operation; {error}".format(error=err)) mysql.connector.errors.InterfaceError: Failed executing the operation;
object of type 'int' has no len()
Any other alternatives are also welcome.
My ultimate goal is to store the encrypted text in database.
I reproduced your error, but it seems there are more errors in your code.
The key as well as the message are strings, therefore I got this error:
TypeError: Object type <class 'str'> cannot be passed to C code
Which I fixed by encoding them in utf-8:
# line 38:
key = str(1234567899876543).encode("utf8")
# .... line 41:
s= encrypt(key, msg.encode("utf8"))
The UNHEX function in your SQL Query is not needed because we are entering the data as VARBINARY. You can change your statement to:
"""insert into test1 values(%s) """
The function executemany() can be replaced by execute() because you are only entering one statement. However I will write the solution for using both, execute or executemany.
insert with execute():
From the documentation:
cursor.execute(operation, params=None, multi=False)
iterator = cursor.execute(operation, params=None, multi=True)
This method executes the given database operation (query or command). The parameters found in the tuple or dictionary params are bound to the variables in the operation. Specify variables using %s or %(name)s parameter style (that is, using format or pyformat style). execute() returns an iterator if multi is True.
https://dev.mysql.com/doc/connector-python/en/connector-python-api-mysqlcursor-execute.html
So we need just to build a tuple with your parameters by changing the cursor.execute line to:
cursor.execute(sql_para_query, (db, ))
insert with executemany():
From the documentation:
cursor.executemany(operation, seq_of_params)
This method prepares a database operation (query or command) and executes it against all parameter sequences or mappings found in the sequence seq_of_params.
https://dev.mysql.com/doc/connector-python/en/connector-python-api-mysqlcursor-executemany.html
Therefore we need to build a sequence with values you'd like to insert. In your case just one value:
cursor.executemany(sql_para_query, [(db, )])
To insert multiple values, you can add as many tuples into your sequence as you want.
full code:
import ast
import mysql.connector
from Crypto.Cipher import AES
from Crypto.Random import get_random_bytes
def encrypt(key, msg):
iv = get_random_bytes(16)
cipher = AES.new(key, AES.MODE_CFB, iv)
ciphertext = cipher.encrypt(msg) # Use the right method here
db = iv + ciphertext
cursor.execute(sql_para_query, (db, ))
connection.commit()
return iv + ciphertext
def decrypt(key, ciphertext):
iv = ciphertext[:16]
ciphertext = ciphertext[16:]
cipher = AES.new(key, AES.MODE_CFB, iv)
msg = cipher.decrypt(ciphertext)
return msg.decode("utf-8")
if __name__ == "__main__":
connection = mysql.connector.connect(host = "localhost", database = "test_db", user = "sann", password = "userpass",use_pure=True)
cursor = connection.cursor(prepared = True)
sql_para_query = """insert into test1 values(%s) """
ed = input("(e)ncrypt or (d)ecrypt: ")
key = str(1234567899876543).encode("utf8")
if ed == "e":
msg = input("message: ")
s= encrypt(key, msg.encode("utf8"))
print("Encrypted message: ", s)
file = open("e_tmp","wb+")
file.write(s)
print(type(s))
elif ed == "d":
sql_para_query = """select * from test1"""
cursor.execute(sql_para_query)
row = cursor.fetchone()
msg = row[0] # row is a tuple, therefore get first element of it
print("Unencrypted message: ", msg)
s=decrypt(key, msg)
print("Decrypted message: ", s)
output:
#encrypt:
(e)ncrypt or (d)ecrypt: e
message: this is my test message !!
Encrypted message: b"\x8f\xdd\xe6f\xb1\x8e\xb51\xc1'\x9d\xbf\xb5\xe1\xc7\x87\x99\x0e\xd4\xb2\x06;g\x85\xc4\xc1\xd2\x07\xb5\xc53x\xb9\xbc\x03+\xa2\x95\r4\xd1*"
<class 'bytes'>
#decrypt:
(e)ncrypt or (d)ecrypt: d
Unencrypted message: bytearray(b"\x8f\xdd\xe6f\xb1\x8e\xb51\xc1\'\x9d\xbf\xb5\xe1\xc7\x87\x99\x0e\xd4\xb2\x06;g\x85\xc4\xc1\xd2\x07\xb5\xc53x\xb9\xbc\x03+\xa2\x95\r4\xd1*")
Decrypted message: this is my test message !!
I have written a code using if, try/except clause. I want to use "try" to check whether the parameters are correct and if those are correct the "print" function will run.
If the parameters are not right then the error message will be printed and the print section will not run.
The problem is when I am correct input it is running but when I am giving wrong input, after printing the error message I am getting NameError, saying "room1" is not defined. I understood why it is happening but I am confused how to get the correct output without getting an error.
My code is:
class Hotel:
def __init__(self,room,catagory):
if type(room) != int:
raise TypeError()
if type(catagory) != str:
raise TypeError()
self.room = room
self.catagory = catagory
self.catagories = {"A":"Elite","B":"Economy","C":"Regular"}
self.rooms = ["0","1","2","3","4","5"]
def getRoom(self):
return self.room
def getCatagory(self):
return self.catagories.get(self.catagory)
def __str__(self):
return "%s and %s"%(self.rooms[self.room],self.catagories.get(self.catagory))
try:
room1 = Hotel(a,"A")
except:
print("there's an error")
print (room1)
Your print should be in the try segment of your code as it will always execute whether there is an error or not.
class Hotel:
def __init__(self,room,catagory):
if type(room) != int:
raise TypeError()
if type(catagory) != str:
raise TypeError()
self.room = room
self.catagory = catagory
self.catagories = {"A":"Elite","B":"Economy","C":"Regular"}
self.rooms = ["0","1","2","3","4","5"]
def getRoom(self):
return self.room
def getCatagory(self):
return self.catagories.get(self.catagory)
def __str__(self):
return "%s and %s"%(self.rooms[self.room],self.catagories.get(self.catagory))
Initialization
try:
room1 = Hotel(a,"A")
print (room1)
except:
print("there's an error")