Develop Reference

Problems with pickle python

I recently made a program using an external document with pickle. But when it tries to load the file with pickle, I got this error (the file is already existing but it also fails when the file in't existing):
python3.6 check-graph_amazon.py
a
b
g
URL to follow www.amazon.com
Product to follow Pool_table
h
i
[' www.amazon.com', ' Pool_table', []]
p
Traceback (most recent call last):
File "check-graph_amazon.py", line 17, in <module>
tab_simple = pickle.load(doc_simple)
io.UnsupportedOperation: read
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "check-graph_amazon.py", line 42, in <module>
pickle.dump(tab_simple, 'simple_data.dat')
TypeError: file must have a 'write' attribute
Here is the code :
import pickle5 as pickle
#import os
try:
print("a")
with open('simple_data.dat', 'rb') as doc_simple:
print("b")
tab_simple = pickle.load(doc_simple)
print("c")
print(tab_simple)
print("d")
URL = tab_simple[0]
produit_nom = tab_simple[1]
tous_jours = tab_simple[2]
print("f")
except :
print("g")
URL = str(input("URL to follow"))
produit_nom = str(input("Product to follow"))
with open('simple_data.dat', 'wb+') as doc_simple:
print("h")
#os.system('chmod +x simple_data.dat')
tab_simple = []
tab_simple.append(URL)
tab_simple.append(produit_nom)
tab_simple.append([])
print(tab_simple)
print("c'est le 2")
print("p")
pickle.dump(tab_simple, 'simple_data.dat')
print("q")
The prints are here to show which lines are executed. The os.system is here to allow writing on the file but the error is persisting.
I don't understand why it's said that the document doesn't have a write attribute because I opened it in writing mode. And I neither understand the first error where it can't load the file.
If it can help you the goal of this script is to initialise the program, with a try. It tries to open the document in reading mode in the try part and then set variables. If the document doesn't exist (because the program is lauched for the first time) it goes in the except part and create the document, before writing informations on it.
I hope you will have any clue, including changing the architecture of the code if you have a better way to make an initialisation for the 1st time the program is launched.
Thanks you in advance and sorry if the code isn't well formated, I'm a beginner with this website.

Quote from the docs for pickle.dump:
pickle.dumps(obj, protocol=None, *, fix_imports=True)
Write a pickled representation of obj to the open file object file. ...
...
The file argument must have a write() method that accepts a single bytes argument. It can thus be an on-disk file opened for binary writing, an io.BytesIO instance, or any other custom object that meets this interface.
So, you should pass to this function a file object, not a file name, like this:
with open("simple_data.dat", "wb"): as File:
pickle.dump(tab_simple, File)
Yeah, in your case the file has already been opened, so you should write to doc_simple.

P4Python run method does not work on empty folder

I want to search a Perforce depot for files.
I do this from a python script and use the p4python library command:
list = p4.run("files", "//mypath/myfolder/*")
This works fine as long as myfolder contains some files. I get a python list as a return value. But when there is no file in myfolder the program stops running and no error message is displayed. My goal is to get an empty python list, so that I can see that this folder doesn't contain any files.
Does anybody has some ideas? I could not find information in the p4 files documentation and on StackOverflow.

I'm going to guess you've got an exception handler around that command execution that's eating the exception and exiting. I wrote a very simple test script and got this:
C:\Perforce\test>C:\users\samwise\AppData\local\programs\python\Python36-32\python files.py
Traceback (most recent call last):
File "files.py", line 6, in <module>
print(p4.run("files", "//depot/no such path/*"))
File "C:\users\samwise\AppData\local\programs\python\Python36-32\lib\site-packages\P4.py", line 611, in run
raise e
File "C:\users\samwise\AppData\local\programs\python\Python36-32\lib\site-packages\P4.py", line 605, in run
result = P4API.P4Adapter.run(self, *flatArgs)
P4.P4Exception: [P4#run] Errors during command execution( "p4 files //depot/no such path/*" )
[Error]: "//depot/no such path/* - must refer to client 'Samwise-dvcs-1509687817'."

Try something like this ?
import os
if len(os.listdir('//mypath/myfolder/') ) == 0: # Do not execute p4.run if directory is empty
list = []
else:
list = p4.run("files", "//mypath/myfolder/*")

Compiled Extension File error Report in LiClipse Python

doc_holder_str = ''
sample_H_value = open("C:\testGupixwin\BX-N-H.HED", "r")
standard_conc_value = open("C:\testGupixwin\gupixwin_H_stdConc.txt", "r")
sample_H_value_str = sample_H_value.readline()
while sample_H_value_str is not '' :
stripper_sample_H = float(sample_H_value_str[5:].lstrip(' '))
I'm trying to write a piece of code (as shown above) which reads some values, do some calculations on it and returns the said values. I am using the LiClipse IDE, for python.
I have tested my code and it works, but when I tried to run it with real data, ( for which I created a new folder to put in all the files I will be working with) I received an OS error suggesting I inserted an invalid argument.
The error report says ;
Traceback (most recent call last):
File "C:\Python34\workspace\Gupixwin_Project.py", line 11, in <module>
sample_H_value = open("C:\testGupixwin\BX-N-H.HED", "r")
OSError: [Errno 22] Invalid argument: 'C:\testGupixwin\\BX-N-H.HED'
on clicking on the C:\testGupixwin\\BX-N-H.HED it bring up a message box suggesting, and I quote,
The definition was found at C:\testGupixwin\BX-N-H.HED, (which
cannot be opened because it is a compiled extension)
I must point out that I feel the error is that the system sees ...\\BX-N.... Instead of ..\BX-N... Which I expect.
Some one suggested I do this
[Open Window -> Preferences, goto PyDev -> Editor -> Code Style ->
File Types, look for "Valid source files (comma-separated)" and append
", log".]
I HAVE DONE THIS BUT I STILL GET THE OSERROR REPORT.
Thanks for any assistance

I think the problem is the escaping with \
alternate the string in: open("C:\testGupixwin\BX-N-H.HED", "r")
with:
open( r"C:\testGupixwin\BX-N-H.HED", "r" ) #rawstring
# or
open( "C:\\testGupixwin\\BX-N-H.HED", "r" ) #escaping the '\' with '\'
(also do this in the following line)

struct.error: argument for 's' must be a string

i'm working on a authentication system with raspberry pi with the Fingerprint Scanner - TTL (GT-511C3) and i have a function that create a template and returns as result the following :
I want to extract only th data part so i did like this : response 1['Data']
but when i print it i get this :
i added this as header of my file :
reload(sys)
sys.setdefaultencoding('utf8')
and i tried a couple of solutions i found in the forum but i couldn't find one that works with me.
my problem is when i try to compare the created template with the ones already in the database of the scanner with a function called IdentifyTemplate and takes as a parameter a template it gives me the following error :
Traceback (most recent call last):
File "finger.py", line 169, in
indetifyResponse = f.IdentifyTemplate(makeTemplateResponse)
File "/home/pi/Desktop/fingerpi/fingerpi/fingerpi.py", line 213, in
IdentifyTemplate
if self.sendData(template, 498):
File "/home/pi/Desktop/fingerpi/fingerpi/fingerpi.py", line 53, in sendData
packet = encode_data_packet(data, data_len, device_id = self.device_id)
File "/home/pi/Desktop/fingerpi/fingerpi/base.py", line 72, in
encode_data_packet
data # Data to be sent
struct.error: argument for 's' must be a string
i suspect that the problem is comming from that Data that i'm trying to print.
Any help is much appreciated. My Python version is 2.7.13

Something wrong with ViewClient.connectToDeviceOrExit()

I'm recently started to use python with mobile app automation, as i decided to use python, the main instruments that I've found were monkeyrunner and androidviewclient.
But there is the first issue with which i dont know what to do:
package = 'com.mypackage.android'
activity = '.launchActivity'
component = package + "/" + activity
device, serialno = ViewClient.connectToDeviceOrExit()
device.startActivity(component=component)
time.sleep(3)
vc = ViewClient(device, serialno)
vc.dump()
showMenu = vc.findViewById("id/no_id/8")
showMenu.touch()
as i'm running it in windows cmd - monkeyrunner mypath\test-case1.py
i receive an exception:
131213 18:42:32.555:S [MainThread] [com.android.monkeyrunner.MonkeyRunnerOptions] Script terminated due to an exception
131213 18:42:32.555:S [MainThread] [com.android.monkeyrunner.MonkeyRunnerOptions]Traceback (most recent call last):
File "C:\Python27\tests\1.py", line 26, in <module>
device, serialno = ViewClient.connectToDeviceOrExit()
File "C:\Program Files (x86)\Android\AndroidViewClient\AndroidViewClient-maste
r\AndroidViewClient\src\com\dtmilano\android\viewclient.py", line 1381, in conne
ctToDeviceOrExit
ViewClient.setAlarm(timeout+5)
File "C:\Program Files (x86)\Android\AndroidViewClient\AndroidViewClient-maste
r\AndroidViewClient\src\com\dtmilano\android\viewclient.py", line 1341, in setAl
arm
signal.alarm(timeout)
File "C:\Program Files (x86)\Android\android-sdk\tools\lib\jython-standalone-2
.5.3.jar\Lib\signal.py", line 222, in alarm
NotImplementedError: alarm not implemented on this platform
am I doing something wrong? Please help.
Thank you a lot!

This is how setAlarm looks like
#staticmethod
def setAlarm(timeout):
osName = platform.system()
if osName.startswith('Windows'): # alarm is not implemented in Windows
return
signal.alarm(timeout)
so, it tries to identify that is Windows and then not invoking signal.alarm() which is not implemented, but for some reason it fails in your case.
Try to print the result of osName to see what went wrong.
UPDATE
Now I see, you are using monkeyrunner as the interpreter but AndroidViewClient >= 4.0.0 is 100% pure python, so you should run your scripts using a python 2.x interpreter.