Develop Reference

Not allowing the developer to use the print method

I have developed a python framework that is being used by others. In order to print any data to the output, the developer should use a Log class (Log.print(...)) and should not use the print() method directly. Is there any ways to force this rule throughout the code? For example, by throwing an error when a developer uses the print method directly like this:
Error: print method cannot be called directly. Please use Log.print().
Suppressing print (as discussed here) is not a good idea as the developer might get confused.

Actullay, below two line code are the same:
sys.stdout.write('hello'+'\n')
print('hello')
so, you can redirect sys.stdout to a class which raise a exception at calling print.
import sys
class BlockPrint():
call_print_exception = Exception('Error: print method cannot be called directly. Please use Log.print().')
def write(self, str):
raise self.call_print_exception
bp = BlockPrint()
sys.stdout=bp
print('aaa')
Output:
Traceback (most recent call last):
File "p.py", line 12, in <module>
print('aaa')
File "p.py", line 7, in write
raise self.call_print_exception
Exception: Error: print method cannot be called directly. Please use Log.print().

How can I pass a function to a class's method in python?

I'm trying to write a thing you can pass your service check code to and alert if it returns false - in python how can I pass code to an instance of a thing?
#!/usr/bin/env python
def service_check():
print('service is up')
class Alerter():
def watch(f):
f()
watcher = Alerter()
watcher.watch(service_check())
returns:
service is up
Traceback (most recent call last):
File "./service_alert", line 12, in <module>
watcher.watch(service_check())
TypeError: watch() takes exactly 1 argument (2 given)

Here is working Code
def service_check():
print('service is up')
class Alerter():
def watch(self,f):
f()
watcher = Alerter()
watcher.watch(service_check)
As #Tomothy32 mention there are 2 changes.
Need to add Self in def watch(self,f). This is because, whenever an object calls its method, the object itself is passed as the first argument.
The second we should pass function pointer watcher.watch(service_check) instead of function calling watcher.watch(service_check()).

watch() function is missing an argument to self due to which the above program throws an exception. Also, You should just pass the name of the function to pass its address in watcher.watch(service_check) instead of making a call via service_check().
Program should work fine with these changes as suggested by #arunraja-a.

TypeError: object() takes no parameters (trex dino bot)

how can i solve this problem please tell me what to do
this i am not able to figure out this problem. so please do tell me how to solve this in simple words.
import time
from PIL import ImageGrab
import pyautogui
class Cordinates():
replayBtn = (340,420)
dinosaur = (422,170)
#215= xcordinate to check for tree
def restartGame():
pyautogui.click(Cordinates.replayBtn)
def pressSapce():
pyautogui.keyDown('space')
time.sleep(0.05)
print("Jump")
pyautogui.KeyUp('space')
restartGame()
time.sleep(1)
pressSapce()
after runing i get
C:\Users\Pranav\PycharmProjects\untitled1\venv\Scripts\python.exe
C:/Users/Pranav/PycharmProjects/untitled1/bot.py
Traceback (most recent call last):
Jump
File "C:/Users/Pranav/PycharmProjects/untitled1/bot.py", line 22, in <module>
pressSapce()
File "C:/Users/Pranav/PycharmProjects/untitled1/bot.py", line 18, in pressSapce
pyautogui.KeyUp('space')
TypeError: object() takes no parameters
Process finished with exit code 1
how to solve :-
pyautogui.KeyUp('space')
TypeError: object() takes no parameters
what do you mean by the above message

you need to use keyUp not KeyUp with capital letter docs
pyautogui.keyUp('space')

pyautogui.KeyUp('space')
is supposed to be
pyautogui.keyUp('space')
That should fix your problem.

Telegram TypeError: the first argument must be callable

I'm trying to do post automatic schedule in Telegram. It runs first run but after its try to looping I get an error:
TypeError: the first argument must be callable
My code :
import time
import schedule
from pyrogram import Client, ReplyKeyboardMarkup, InlineKeyboardMarkup, InlineKeyboardButton
from pyrogram.api import functions, types
from pyrogram.api.errors import FloodWait
person1 = Client(
session_name="*cenzored*",
api_id=*cenzored*,
api_hash="*cenzored*"
)
person2 = Client(
session_name="*cenzored*",
api_id=*cenzored*,
api_hash="*cenzored*"
)
wick.start()
def Publish(session,dat,msgid,session_name):
try:
session.start()
print("[%s]Posting..." % (session_name))
session.send(
functions.messages.GetBotCallbackAnswer(
peer=session.resolve_peer("*cenzored*"),
msg_id=msgid,
data=b'publish %d' % (dat)
)
)
session.idle()
except:
print("Crashed,starting over")
schedule.every(0.3).minutes.do(Publish(person1,142129,12758, 'Dani')) // Here is the line is crashing.
schedule.every(0.3).minutes.do(Publish(person2,137351,13177, 'Wick'))
while 1:
schedule.run_pending()
time.sleep(1)
Traceback :
Pyrogram v0.7.4, Copyright (C) 2017-2018 Dan Tès <https://github.com/delivrance>
Licensed under the terms of the GNU Lesser General Public License v3 or later (LGPLv3+)
[person1]Posting...
3: 2018-06-16 12:07:26.529829 Retrying <class 'pyrogram.api.functions.messages.get_bot_callback_answer.GetBotCallbackAnswer'>
4: 2018-06-16 12:07:42.041309 Retrying <class 'pyrogram.api.functions.messages.get_bot_callback_answer.GetBotCallbackAnswer'>
Crashed,starting over
Traceback (most recent call last):
File "C:\Users\343df\OneDrive\Desktop\Maor\python\tele\tele.py", line 35, in <module>
schedule.every(0.3).minutes.do(Publish('ss',dani,140129,12758, 'Dani'))
File "C:\Program Files (x86)\Python36-32\lib\site-packages\schedule\__init__.py", line 385, in do
self.job_func = functools.partial(job_func, *args, **kwargs)
TypeError: the first argument must be callable
Basically my problem is that is not running (TypeError: the first argument must be callable) after first time and its scheduled to run every 0.3 seconds.

According to [ReadTheDocs]: do(job_func, *args, **kwargs), you don't have to call Publish, but just pass it, followed by its argument list (the call will be performed by schedule framework):
schedule.every(0.3).minutes.do(Publish, person1, 142129, 12758, "Dani")
schedule.every(0.3).minutes.do(Publish, person2, 137351, 13177, "Wick")

.do() expects a callable as the first argument (and additional arguments to .do will be passed to that callable).
So instead of:
schedule.every(0.3).minutes.do(Publish(person1,142129,12758, 'Dani'))
schedule.every(0.3).minutes.do(Publish(person2,137351,13177, 'Wick'))
you likely want:
schedule.every(0.3).minutes.do(Publish, person1, 142129, 12758, 'Dani')
schedule.every(0.3).minutes.do(Publish, person2, 137351, 13177, 'Wick')

Unbound method must be called with X instance as first argument (got str instance instead)

I am playing with pyelliptic, but I can't use the method raw_get_ecdh_key defined in the file ecc.py.
Here's my example code:
>>> import pyelliptic
>>> pubkey1="0453eb8248f42b00d057bc1adc724c4c841ec75851d6cd86f56f9bae5223219c7d3c7aff832d2383dfec167327ef38e9bf066690a8f94c055b336a607cebc2dddf".decode('hex')
>>> pubkey2="04678b95e902b04817ba258ecd3dbb2150d83850848a3b8523c11d51b6a9f89b93ea82db74ba82ba44fadb050b35eae8b96f3738e88c7c117227303a528c8df985".decode('hex')
>>> pyelliptic.ECC.raw_get_ecdh_key(pubkey1, pubkey2)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
TypeError: unbound method raw_get_ecdh_key() must be called with ECC instance as first argument (got str instance instead)
I searched and found many questions on the subject here. I learned that I need to call ECC() instead of ECC, but it doesn't work any better:
>>> pyelliptic.ECC().raw_get_ecdh_key(pubkey1, pubkey2)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/local/lib/python2.7/dist-packages/pyelliptic/ecc.py", line 324, in raw_get_ecdh_key
OpenSSL.EC_KEY_free(own_key)
UnboundLocalError: local variable 'own_key' referenced before assignment
I can't figure what's wrong. I checked and the variable own_key should be referenced.

It's a very obvious bug in pyelliptic - if you look at the code, the part where own_key is defined (ecc.py line 301) is wrapped in huge try/finally block. If an exception is raised (and not managed) before line 301 (which is obviously what happened to you), then the execution flow jumps to the finally block, which to tries to reference own_key which at this point has not yet been defined.
You can fix by cloning the git repo and editing the raw_get_ecdh_key function's code so 1. the relevant local variables are defined at the beginning of the function before the try block (setting them to None) and 2. in the finally block these variables are tested against None before trying to use them to free resources, ie (untested):
def raw_get_ecdh_key(self, pubkey_x, pubkey_y):
other_key = None
other_pub_key_x = None
other_pub_key_y = None
other_pub_key = None
own_key = None
own_priv_key = None
try:
# (snip code)
finally:
if other_key is not None:
OpenSSL.EC_KEY_free(other_key)
if other_pub_key_x is not None:
OpenSSL.BN_free(other_pub_key_x)
if other_pub_key_y is not None:
OpenSSL.BN_free(other_pub_key_y)
if other_pub_key is not None:
OpenSSL.EC_POINT_free(other_pub_key)
if own_key is not None:
OpenSSL.EC_KEY_free(own_key)
if own_priv_key is not None:
OpenSSL.BN_free(own_priv_key)
And then run the the unittests (eventually adding some tests for this case) and submit a pull request to the author.
Note that you'll have applied this (untested) fix you should have another error - the one that sent you in the finally block at first - but at least you should then have more infos about why the call failed.