Re: Python in Blender. Writing information to a file.
On 09Aug2019 20:53, Paul St George wrote:
I almost understand.
Are you saying I should change the first line of code to something
like:
|outstream = with open(path to my file,'w') # this is invalid syntax|
and then delete the
outstream.close()
No, you should do what Peter wrote:
with open("/path/to/file", "w") as outstream:
print(my_stuff, file=outstream)
Got it! I hadn't taken Peter's advice as code. I thought (well anyway now I
have it). So thanks to Peter, Cameron and
Rhodri.
No worries. You should also got and look up "context manager" in the
Python docs.
It is a general mechanism where you can write:
with something as name:
suite of code
where "something" is an object which implements a context manager.
Before "suite of code" starts Python calls "something.__enter__" and
when the interpreter leaves the suite Python calls "something.__exit__".
Notably, it will call __exit__ no matter how you leave the suite: as
usual, by falling off the end, or early with an exception or a break or
a continue or a return. The __exit__ function always gets called.
In the case Peter's example, "something" is "open()": the file object
you get back from open() implements a context manager. Its __enter__
function does nothing, but its __exit__ function closes the file.
Reliably and immediately.
Cheers, Cameron Simpson (formerly c...@zip.com.au)
I swear to god, officer, I'm fixing this bridge. Just go divert traffic.
--
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Re: Re: Python in Blender. Writing information to a file.
On 09/08/2019 15:59, Rhodri James wrote:
On 09/08/2019 14:54, Paul St George wrote:
On 09/08/2019 04:09, Cameron Simpson wrote:
On 08Aug2019 22:42, Paul St George wrote:
On 08/08/2019 10:18, Peter Otten wrote:
The print() function has a keyword-only file argument. So:
with open(..., "w") as outstream:
print("Focal length:", bpy.context.object.data.lens,
file=outstream)
[...]
That worked perfectly.
outstream = open(path to my file,'w')
print(
whatever I want to print
file=outstream
)
outstream.close()
I just wanted to point out Peter's use of the open context manager:
with open(..., "w") as outstream:
print stuff ...
You'll notice that it does not overtly close the file. The file
object returned from open() is a context manager, the "with"
statement arranges to close the file when your programme exits the
with suite.
Importantly, the close will happen even if the code inside raises an
exception, which in your "open..print..close" sequence would not
reach the close call.
So we recommend the "with" form of open() above.
There are circumstances where it isn't useful, but they are very rare.
Cheers,
Cameron Simpson
I almost understand.
Are you saying I should change the first line of code to something like:
|outstream = with open(path to my file,'w') # this is invalid syntax|
and then delete the
outstream.close()
No, you should do what Peter wrote:
with open("/path/to/file", "w") as outstream:
print(my_stuff, file=outstream)
Got it! I hadn't taken Peter's advice as code. I thought (well anyway now I
have it). So thanks to Peter, Cameron and
Rhodri.
--
https://mail.python.org/mailman/listinfo/python-list
Re: Python in Blender. Writing information to a file.
On 09/08/2019 14:54, Paul St George wrote:
On 09/08/2019 04:09, Cameron Simpson wrote:
On 08Aug2019 22:42, Paul St George wrote:
On 08/08/2019 10:18, Peter Otten wrote:
The print() function has a keyword-only file argument. So:
with open(..., "w") as outstream:
print("Focal length:", bpy.context.object.data.lens,
file=outstream)
[...]
That worked perfectly.
outstream = open(path to my file,'w')
print(
whatever I want to print
file=outstream
)
outstream.close()
I just wanted to point out Peter's use of the open context manager:
with open(..., "w") as outstream:
print stuff ...
You'll notice that it does not overtly close the file. The file object
returned from open() is a context manager, the "with" statement
arranges to close the file when your programme exits the with suite.
Importantly, the close will happen even if the code inside raises an
exception, which in your "open..print..close" sequence would not reach
the close call.
So we recommend the "with" form of open() above.
There are circumstances where it isn't useful, but they are very rare.
Cheers,
Cameron Simpson
I almost understand.
Are you saying I should change the first line of code to something like:
|outstream = with open(path to my file,'w') # this is invalid syntax|
and then delete the
outstream.close()
No, you should do what Peter wrote:
with open("/path/to/file", "w") as outstream:
print(my_stuff, file=outstream)
--
Rhodri James *-* Kynesim Ltd
--
https://mail.python.org/mailman/listinfo/python-list
Re: Python in Blender. Writing information to a file.
On 09/08/2019 04:09, Cameron Simpson wrote:
On 08Aug2019 22:42, Paul St George wrote:
On 08/08/2019 10:18, Peter Otten wrote:
The print() function has a keyword-only file argument. So:
with open(..., "w") as outstream:
print("Focal length:", bpy.context.object.data.lens,
file=outstream)
[...]
That worked perfectly.
outstream = open(path to my file,'w')
print(
whatever I want to print
file=outstream
)
outstream.close()
I just wanted to point out Peter's use of the open context manager:
with open(..., "w") as outstream:
print stuff ...
You'll notice that it does not overtly close the file. The file object
returned from open() is a context manager, the "with" statement
arranges to close the file when your programme exits the with suite.
Importantly, the close will happen even if the code inside raises an
exception, which in your "open..print..close" sequence would not reach
the close call.
So we recommend the "with" form of open() above.
There are circumstances where it isn't useful, but they are very rare.
Cheers,
Cameron Simpson
I almost understand.
Are you saying I should change the first line of code to something like:
|outstream = with open(path to my file,'w') # this is invalid syntax|
and then delete the
outstream.close()
--
https://mail.python.org/mailman/listinfo/python-list
Re: Python in Blender. Writing information to a file.
On 08Aug2019 22:42, Paul St George wrote:
On 08/08/2019 10:18, Peter Otten wrote:
The print() function has a keyword-only file argument. So:
with open(..., "w") as outstream:
print("Focal length:", bpy.context.object.data.lens, file=outstream)
[...]
That worked perfectly.
outstream = open(path to my file,'w')
print(
whatever I want to print
file=outstream
)
outstream.close()
I just wanted to point out Peter's use of the open context manager:
with open(..., "w") as outstream:
print stuff ...
You'll notice that it does not overtly close the file. The file object
returned from open() is a context manager, the "with" statement arranges
to close the file when your programme exits the with suite.
Importantly, the close will happen even if the code inside raises an
exception, which in your "open..print..close" sequence would not reach
the close call.
So we recommend the "with" form of open() above.
There are circumstances where it isn't useful, but they are very rare.
Cheers,
Cameron Simpson
--
https://mail.python.org/mailman/listinfo/python-list
Re: Re: Python in Blender. Writing information to a file.
On 08/08/2019 10:18, Peter Otten wrote:
Paul St George wrote:
I am using Python 3.5 within Blender. I want to collect values of the
current settings and then write all the results to a file.
I can see the settings and the values in the Python console by doing
this for each of the settings
|
|
|print(“Focal length:”,bpy.context.object.data.lens)|
---Focal length: 35.0
or I can do many at a time like this:
|print("Plane rotation
X:",bpy.data.objects["Plane"].rotation_euler[0],"\nPlane rotation
Y:",bpy.data.objects["Plane"].rotation_euler[1],"\nPlane rotation
Z:",bpy.data.objects["Plane"].rotation_euler[2])|
---Plane rotation X: 0.0
---Plane rotation Y: 0.0
---Plane rotation Z: 0.0
My question:
How do I write all the results to a file? I have tried file.write but
can only write one argument at a time. Is there a better way to open a
file, write the collected information to it and then close the file?
The print() function has a keyword-only file argument. So:
with open(..., "w") as outstream:
print("Focal length:", bpy.context.object.data.lens, file=outstream)
|print("Plane rotation
X:",bpy.data.objects["Plane"].rotation_euler[0],"\nPlane rotation
Y:",bpy.data.objects["Plane"].rotation_euler[1],"\nPlane rotation
Z:",bpy.data.objects["Plane"].rotation_euler[2])|
This looks messy to me. I' probably use intermediate variables
x, y, z = bpy.data.objects["Plane"].rotation_euler
print(
"Plane rotation X:", x,
"Plane rotation Y:", y,
"Plane rotation Z:", z,
file=outstream, sep="\n"
)
or even a loop.
That worked perfectly.
outstream = open(path to my file,'w')
print(
whatever I want to print
file=outstream
)
outstream.close()
--
https://mail.python.org/mailman/listinfo/python-list
Re: Python in Blender. Writing information to a file.
Paul St George wrote:
> I am using Python 3.5 within Blender. I want to collect values of the
> current settings and then write all the results to a file.
>
> I can see the settings and the values in the Python console by doing
> this for each of the settings
> |
> |
>
> |print(“Focal length:”,bpy.context.object.data.lens)|
>
> ---Focal length: 35.0
>
>
> or I can do many at a time like this:
>
> |print("Plane rotation
> X:",bpy.data.objects["Plane"].rotation_euler[0],"\nPlane rotation
> Y:",bpy.data.objects["Plane"].rotation_euler[1],"\nPlane rotation
> Z:",bpy.data.objects["Plane"].rotation_euler[2])|
>
> ---Plane rotation X: 0.0
> ---Plane rotation Y: 0.0
> ---Plane rotation Z: 0.0
>
>
> My question:
> How do I write all the results to a file? I have tried file.write but
> can only write one argument at a time. Is there a better way to open a
> file, write the collected information to it and then close the file?
>
The print() function has a keyword-only file argument. So:
with open(..., "w") as outstream:
print("Focal length:", bpy.context.object.data.lens, file=outstream)
> |print("Plane rotation
> X:",bpy.data.objects["Plane"].rotation_euler[0],"\nPlane rotation
> Y:",bpy.data.objects["Plane"].rotation_euler[1],"\nPlane rotation
> Z:",bpy.data.objects["Plane"].rotation_euler[2])|
This looks messy to me. I' probably use intermediate variables
x, y, z = bpy.data.objects["Plane"].rotation_euler
print(
"Plane rotation X:", x,
"Plane rotation Y:", y,
"Plane rotation Z:", z,
file=outstream, sep="\n"
)
or even a loop.
--
https://mail.python.org/mailman/listinfo/python-list
Python in Blender. Writing information to a file.
I am using Python 3.5 within Blender. I want to collect values of the
current settings and then write all the results to a file.
I can see the settings and the values in the Python console by doing
this for each of the settings
|
|
|print(“Focal length:”,bpy.context.object.data.lens)|
---Focal length: 35.0
or I can do many at a time like this:
|print("Plane rotation
X:",bpy.data.objects["Plane"].rotation_euler[0],"\nPlane rotation
Y:",bpy.data.objects["Plane"].rotation_euler[1],"\nPlane rotation
Z:",bpy.data.objects["Plane"].rotation_euler[2])|
---Plane rotation X: 0.0
---Plane rotation Y: 0.0
---Plane rotation Z: 0.0
My question:
How do I write all the results to a file? I have tried file.write but
can only write one argument at a time. Is there a better way to open a
file, write the collected information to it and then close the file?
--
https://mail.python.org/mailman/listinfo/python-list
