AttributeError: 'function' object has no attribute 'isatty' (progress.py, line 163)

[jonturneratduke]

The library is throwing the following exception w. MacOS High Sierra 10.13.6 (17G8030):

  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/alive_progress/progress.py", line 163, in alive_bar
    if sys.stdout.isatty() or config.force_tty:
AttributeError: 'function' object has no attribute 'isatty'
```. Need to first check if sys.stdout is not null in case output is being supressed?

[rogerio-geru]

Hello @jonturneratduke

That's weird, it does work on Python 3.7:

 ~ $ ipython
Python 3.7.4 (default, Sep 29 2019, 03:13:35) 
Type 'copyright', 'credits' or 'license' for more information
IPython 7.8.0 -- An enhanced Interactive Python. Type '?' for help.

In [1]: import sys                                                                                                                                                                       

In [2]: sys.stdout                                                                                                                                                                       
Out[2]: <_io.TextIOWrapper name='<stdout>' mode='w' encoding='UTF-8'>

In [3]: from alive_progress import alive_bar 
   ...: import time                                                                                                                                                                      

In [4]: with alive_bar(1000) as bar: 
   ...:     for i in range(1000): 
   ...:         time.sleep(.01) 
   ...:         bar() 
   ...:                                                                                                                                                                                  
|████████████████████████████████████████| 1000/1000 [100%] in 10.2s (98.47/s) 

In [5]: sys.stdout.isatty()                                                                                                                                                              
Out[5]: True

[rogerio-geru]

Ohh I see, you are using the Python provided by the system? Python.framework

I'll try to find out if the MacOS one have something different.
But in the meantime, you could install Python via pyenv (the best one, which I totally recommend), or via homebrew.

[jonturneratduke]

running Python v3.7.5. I saw this behavior with v1.1 and the latest v1.3 of alive-progress. I'll see if I can use pyenv, it gets complicated with our build system and packaging(using pyinstaller) on a remote gitlab runner...

[jonturneratduke]

Although I'm not sure of the reason for the sys.stdout.isatty() being null, this at least safely checks the condition without throwing an exception. progress.py @ line 163

-     if sys.stdout.isatty() or config.force_tty:
+    isatty_op = getattr(sys.stdout, "isatty", None)
+    if callable(isatty_op):
+        isatty = isatty_op()
+    else:
+        isatty = False
+    if isatty or config.force_tty:

edit: refer to isatty() method. And in the code, call it if it's available.

[rogerio-geru]

But the error does not say null anywhere, it says the attribute isatty was not found in function.
So, the sys.stdout must have returned a function, which did not have the said attribute.

I do install a hook in stdout at some point, but this line should have already ran...

Could you please post the complete stacktrace? Maybe there's something more there.

[jonturneratduke]

So, the sys.stdout must have returned a function, which did not have the said attribute.

You're correct. Sorry for my lack of precision. The isatty method/attribute reference is null, not the parent object.

Exception ignored in: <function AzureProgressBarCallback.__del__ at 0x10dd5e8c0> cli/build/capsule/PKG-00.pkg
Traceback (most recent call last):
  File "cli/src/capsule/utils/azureUtils.py", line 674, in __del__
    self._pb.__exit__(None, None, None)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/contextlib.py", line 119, in __exit__
    next(self.gen)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/alive_progress/progress.py", line 164, in alive_bar
    if sys.stdout.isatty() or config.force_tty:
AttributeError: 'function' object has no attribute 'isatty'

So to explain what's going on, azureUtils.py is calling Azure's download method ane passing a reference to a callback. Azure's library thread calls that callback, which creates your progressbar, and the callback periodically updates the bar's status.

[jonturneratduke]

@rogerio-geru any thoughts on whether the code above (#17 (comment)) would be a suitable patch?

[rogerio-geru]

Hello @jonturneratduke

I did understand what did happen, it should not be needed.
Your code is trying to create another alive-bar, while there is already one in place.
Note the complete exception shows that it ocurred in __del__ and was actually ignored:
Exception ignored in: <function AzureProgressBarCallback.__del__ at 0x10dd5e8c0> cli/build/capsule/PKG-00.pkg

So, after being used, your AzureProgressBarCallback was being destroyed, while there was another already created.

I can simulate by doing manually this:

In [1]: from alive_progress import alive_bar                                                                                                                                             

In [2]: pb = alive_bar()                                                                                                                                                                 

In [3]: pb.__enter__()                                                                                                                                                                   
on 0: <function alive_progress.progress.alive_bar.<locals>.bar(text=None, incr=1)>
on 0: 
In [4]:                                                                                                                                                                                  
on 0: 
In [4]: pb2 = alive_bar()                                                                                                                                                                
on 0: 
In [5]: pb2.__enter__()                                                                                                                                                                  
on 0: ---------------------------------------------------------------------------
      AttributeError                            Traceback (most recent call last)
      <ipython-input-5-11d9d01a04a1> in <module>
      ----> 1 pb2.__enter__()
      
      ~/.pyenv/versions/3.7.4/lib/python3.7/contextlib.py in __enter__(self)
          110         del self.args, self.kwds, self.func
          111         try:
      --> 112             return next(self.gen)
          113         except StopIteration:
          114             raise RuntimeError("generator didn't yield") from None
      
      ~/.pyenv/versions/3.7.4/envs/segregation/lib/python3.7/site-packages/alive_progress/progress.py in alive_bar(total, title, calibrate, **options)
          161 
          162     event = threading.Event()
      --> 163     if sys.stdout.isatty() or config.force_tty:
          164         @contextmanager
          165         def pause_monitoring():
      
      AttributeError: 'function' object has no attribute 'isatty'
on 0: 
|                          ▶▶▶▶▶▶▶▶▶▶▶▶▶ | ▃▁▃ 0 in 40s (0.0/s) (0.0/s)                                                                                                                  

[rogerio-geru]

Well, I think I can proxy the isatty method inside my print hook, no problem.
But do note the best solution would be your code not create two bars at the same time, this is a very non standard way of use.

[rsalmei]

Related to #20

[rsalmei]

Fixed in 1.3.3, please let me know if that's ok.