How do I check for multiple exceptions in Python? - exception

DNASequence = "laksjfklsajdfklsajfklasjfklsad"
while True:
lMerLength = input("Please enter the length of the l-mers of the universal array :")
try:
if len(DNASequence) >= lMerLength > 0:
break
except SyntaxError:
pass
#This is not working. How do I check for multiple exceptions in Python?
except NameError:
pass
print "ERROR: Please check your input. You entered an invalid input."

Here is how you check for multiple exceptions.
try:
..............
except (SyntaxError, NameError, ...):
..............
finally:
.............

The problem is, that input returns a string and you compare that string in your if to an int. And in python 2.x you should use raw_input instead of input:
DNASequence = "laksjfklsajdfklsajfklasjfklsad"
while True:
try:
lMerLength = int(raw_input("Please enter the length of the l-mers of the universal array :"))
except ValueError:
print "ERROR: Please check your input. You entered an invalid input."
continue
if len(DNASequence) >= lMerLength > 0:
break
print "ERROR: Please check your input. You entered an invalid input."

Related

Why am I not being able of detecting a None value from a dictionary

I have seen this issue many times happening to many people (here). I am still struggling trying to validate whether what my dictionary captures from a JSON is "None" or not but I still get the following error.
This code is supposed to call a CURL looking for the 'closed' value in the 'status' key until it finds it (or 10 times). When payment is done by means of a QR code, status changes from opened to closed.
status = (my_dict['elements'][0]['status'])
TypeError: 'NoneType' object is not subscriptable
Any clue of what am I doing wrong and how can I fix it?
Also, if I run the part of the script that calls the JSON standalone, it executes smoothly everytime. Is it anything in the code that could be affecting the CURL execution?
By the way, I have started programming 1 week ago so please excuse me if I mix concepts or say something that lacks of common sense.
I have tried to validate the IF with "is not" instead of "!=" and also with "None" instead of "".
def show_qr():
reference_json = reference.replace(' ','%20') #replaces "space" with %20 for CURL assembly
url = "https://api.mercadopago.com/merchant_orders?external_reference=" + reference_json #CURL URL concatenate
headers = CaseInsensitiveDict()
headers["Authorization"] = "Bearer MY_TOKEN"
pygame.init()
ventana = pygame.display.set_mode(window_resolution,pygame.FULLSCREEN) #screen settings
producto = pygame.image.load("qrcode001.png") #Qr image load
producto = pygame.transform.scale(producto, [640,480]) #Qr size
trials = 0 #sets while loop variable start value
status = "undefined" #defines "status" variable
while status != "closed" and trials<10: #to repeat the loop until "status" value = "closed"
ventana.blit(producto, (448,192)) #QR code position setting
pygame.display.update() #
response = requests.request("GET", url, headers=headers) #makes CURL GET
lag = 0.5 #creates an incremental 0.5 seconds everytime return value is None
sleep(lag) #
json_data = (response.text) #Captures JSON response as text
my_dict = json.loads(json_data) #creates a dictionary with JSON data
if json_data != "": #Checks if json_data is None
status = (my_dict['elements'][0]['status']) #If json_data is not none, asigns 'status' key to "status" variable
else:
lag = lag + 0.5 #increments lag
trials = trials + 1 #increments loop variable
sleep (5) #time to avoid being banned from server.
print (trials)
From your original encountered error, it's not clear what the issue is. The problem is that basically any part of that statement can result in a TypeError being raised as the evaluated part is a None. For example, given my_dict['elements'][0]['status'] this can fail if my_dict is None, or also if my_dict['elements'] is None.
I would try inserting breakpoints to better assist with debugging the cause. another solution that might help would be to wrap each part of the statement in a try-catch block as below:
my_dict = None
try:
elements = my_dict['elements']
except TypeError as e:
print('It possible that my_dict maybe None.')
print('Error:', e)
else:
try:
ele = elements[0]
except TypeError as e:
print('It possible that elements maybe None.')
print('Error:', e)
else:
try:
status = ele['status']
except TypeError as e:
print('It possible that first element maybe None.')
print('Error:', e)
else:
print('Got the status successfully:', status)

Python JSON Decoding With Asynchat Cannot Catch ValueError Exception

I can't seem to catch an exception when using json.loads even though I specifically call it out. I largely see this when trying to stress my server with lots of client connection sending data very quickly. See my error below:
(I've replaced my IP address with X's in the error code)
EX: Unterminated string starting at: line 1 column 49 (char 48) Data:
'{"ap-hdop":0.55,"rtcmin":"38","ap-latdec":3.134,"a' error: uncaptured
python exception, closing channel
(:Unterminated string
starting at: line 1 column 49 (char 48)
[//faraday_server_handler.py|collect_incoming_data|34]
[/usr/lib/python2.7/json/init.py|loads|338]
[/usr/lib/python2.7/json/decoder.py|decode|366]
[/usr/lib/python2.7/json/decoder.py|raw_decode|382])
I understand this that the code fails because I simply miss a double quotes on the line:
'{"ap-hdop":0.55,"rtcmin":"38","ap-latdec":3.134,"a'
This line is usually a LOT longer so that "a.... was supposed to keep going and complete it's quotes.
Here's my relevant code:
def collect_incoming_data(self, data):
"""Read an incoming message from the client, place JSON message data into buffer"""
#self.logger.debug('collect_fing_data() -> (%d bytes)\n"""%s"""', len(data), data)
try:
loaded_data = json.loads(data)
except ValueError, ex:
self.handle_error()
type,value,traceback = sys.exc_info()
print type
#print "Collect Incoming Data: " . time.strftime("%Y-%m-%d %H:%M:%S",time.gmtime())
print "EX: ", ex
print "Data: ",repr(data)
Any ideas? I scoured the internet to see if I can find this issue, but I appear to be setting up to capture the exception which everyone else having this issue with loads seems to suggest to do.
EDIT 3/1/2016 - Evening
Commenting out my exception handle_error() let me see more of the error:
except ValueError, ex:
self.handle_error()
type,value,traceback = sys.exc_info()
print type
#print "Collect Incoming Data: " . time.strftime("%Y-%m-%d %H:%M:%S",time.gmtime())
print "EX: ", ex
print "Data: ",repr(data)
Below is my new error, I've commented out personal data. It's apparent that the issue I really have now is in-fact the unterminated string
EX: Unterminated string starting at:
line 1 column 49 (char 48) Data:
'{"ap-hdop":0.55,"rtcmin":"31","ap-latdec":XX.XXX,"a' EX: No JSON object could be decoded Data:
'p-latdeg":34,"adc6":2006,"adc7":2007,"adc4":2004,"adc5":2005,"adc2":2002,"adc3":2003,"adc0":2000,"adc1":2001,"gpio-0":30,"gpio-1":50,"gpio-2":70,"speed":5.0,"adc8":2008,"rtcday":"01","longdeg":118,"longdec":XX.XXX,"altitude":31.0,"ap-speed":0.0,"ap-pdop":0.77,"lat-dir":"N","long-dir":"W","hdop":0.01,"ap-rf":0,"alt-units":"M","rtcdow":"2","callsign":"XXXXX","ap-callsign":"XXXXX","id":1,"ap-id":1,"rtcyear":"2016","rtcmon":"03","ap-vdop":0.66,"ap-lat-dir":"N","vdop":0.02,"rtchour":"22","latdec":XX.XXX,"latdeg":34,"ap-longdeg":118,"ap-longdec":XX.XXX,"rtcsec":"15","ap-altitude":86.0,"ap-long-dir":"W","pdop":0.01,"ap-alt-units":"M","faraday-port":0}'
OK my original question was answered which was "Why am I not catching the ValueError exception even though I am providing code to do just that?"
#tadhg McDonald-jensen was correct with his comment to remove my call to handle_error().
I still have some other issues but they are a different question. Thanks!

Exception handling using mysql with twisted adbapi and scrapy

I'm using this scrapy pipeline. If there is any error in the sql in the insert_record function, it fails silently. For example, if a column name is miss-spelled, like this
def _insert_record(self, tx, item):
print "before tx.execute"
result = tx.execute(
""" INSERT INTO table(col_one, col_typo, col_three) VALUES (1,2,3)"""
)
print "after tx.execute"
if result > 0:
self.stats.inc_value('database/items_added')
then nothing is output after "before execute". There is a handle_error method but that's not called either. How can I catch and handle such errors?
Just needed to surround it with try...except
try:
result = tx.execute(
"""INSERT INTO table(col_one, col_typo, col_three) VALUES (1,2,3)"""
)
except Exception,e:
print str(e)

World of tanks Python list comparison from json

ok I am trying to create a definition which will read a list of IDS from an external Json file, Which it is doing. Its even putting the data into the database on load of the program, my issue is this. I cant seem to match the list IDs to a comparison. Here is my current code:
def check(account):
global ID_account
import json, httplib
if not hasattr(BigWorld, 'iddata'):
UID_DB = account['databaseID']
UID = ID_account
try:
conn = httplib.HTTPConnection('URL')
conn.request('GET', '/ids.json')
conn.sock.settimeout(2)
resp = conn.getresponse()
qresp = resp.read()
BigWorld.iddata = json.loads(qresp)
LOG_NOTE('[ABRO] Request of URL data successful.')
conn.close()
except:
LOG_NOTE('[ABRO] Http request to URL problem. Loading local data.')
if UID_DB is not None:
list = BigWorld.iddata["ids"]
#print (len(list) - 1)
for n in range(0, (len(list) - 1)):
#print UID_DB
#print list[n]
if UID_DB == list[n]:
#print '[ABRO] userid located:'
#print UID_DB
UID = UID_DB
else:
LOG_NOTE('[ABRO] userid not set.')
if 'databaseID' in account and account['databaseID'] != UID:
print '[ABRO] Account not active in database, game closing...... '
BigWorld.quit()
now my json file looks like this:
{
"ids":[
"1001583757",
"500687699",
"000000000"
]
}
now when I run this with all the commented out prints it seems to execute perfectly fine up till it tries to do the match inside the for loop. Even when the print shows UID_DB and list[n] being the same values, it does not set my variable, it doesn't post any errors, its just simply acting as if there was no match. am I possibly missing a loop break? here is the python log starting with the print of the length of the table print:
INFO: 2
INFO: 1001583757
INFO: 1001583757
INFO: 1001583757
INFO: 500687699
INFO: [ABRO] Account not active, game closing......
as you can see from the log, its never printing the User located print, so it is not matching them. its just continuing with the loop and using the default ID I defined above the definition. Anyone with an idea would definitely help me out as ive been poking and prodding this thing for 3 days now.
the answer to this was found by #VikasNehaOjha it was missing simply a conversion to match types before the match comparison I did this by adding in
list[n] = int(list[n])
that resolved my issue and it finally matched comparisons.

Error in fromJSON(paste(raw.data, collapse = "")) : unclosed string

I am using the R package rjson to download weather data from Wunderground.com. Often I leave the program to run and there are no problems, with the data being collected fine. However, often the program stops running and I get the following error message:
Error in fromJSON(paste(raw.data, collapse = "")) : unclosed string
In addition: Warning message:
In readLines(conn, n = -1L, ok = TRUE) :
incomplete final line found on 'http://api.wunderground.com/api/[my_API_code]/history_20121214pws:1/q/pws:IBIRMING7.json'
Does anyone know what this means, and how I can avoid it since it stops my program from collecting data as I would like?
Many thanks,
Ben
I can recreate your error message using the rjson package.
Here's an example that works.
rjson::fromJSON('{"x":"a string"}')
# $x
# [1] "a string"
If we omit a double quote from the value of x, then we get the error message.
rjson::fromJSON('{"x":"a string}')
# Error in rjson::fromJSON("{\"x\":\"a string}") : unclosed string
The RJSONIO package behaves slightly differently. Rather than throwing an error, it silently returns a NULL value.
RJSONIO::fromJSON('{"x":"a string}')
# $x
# NULL