Re: String slices
On 10/08/2019 10:45, Peter J. Holzer wrote:
On 2019-08-10 09:10:12 +1000, Cameron Simpson wrote:
On 09Aug2019 22:28, Paul St George wrote:
On 09/08/2019 16:29, Rhodri James wrote:
(Actually I would probably use outstream.write() and do my own
formatting, but let's not get side-tracked ;-)
I would love to hear your outstream.write() side-track!
I am not Rhodri James, but you can just write strings to text files:
outstream.write("X: ") # note, includes the space separator
outstream.write(str(thing[0]))
outstring.write("\n")
You can also format the string before passing it to write (which is
probably what Rhodri meant by "do my own formatting", like this:
outstream.write("X: %7.2f\n" % thing[0])
or this
outstream.write("X: {0:7.2f}\n".format(thing[0]))
or (since Python 3.6) this:
outstream.write(f"X: {thing[0]:7.2f}\n")
There are of course many variants to all three methods.
That is indeed what I meant. I do enough random dumping of things to
files for debugging purposes that outstream.write() is second nature to
me now. I once even went as far as sys.stdout.write() before sanity
caught up with me ;-)
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Re: Re: String slices
On 10/08/2019 17:35, Dennis Lee Bieber wrote:
On Sat, 10 Aug 2019 11:45:43 +0200, "Peter J. Holzer"
declaimed the following:
There are of course many variants to all three methods.
And then one can get downright nasty...
X = 3.14
Y = 2.78
Z = 6.226E23
print("".join(["Plane rotation %s: %s\n" % (nm, vl)
... for (nm, vl) in [("X", X), ("Y", Y), ("Z", Z)]]))
Plane rotation X: 3.14
Plane rotation Y: 2.78
Plane rotation Z: 6.226e+23
(replace "print" with "outstream.write" for use with the file)
|outstream.write| could be very useful, thank you Peter and Cameron
(neither being Rhodri James). If I wanted to learn more about formatting
strings is there a better place to go than:
https://docs.python.org/release/3.6.5/library/string.html?highlight=string#format-string-syntax
https://pyformat.info
https://python-reference.readthedocs.io/en/latest/docs/str/formatting.html
And Dennis, whatever you did there is very impressive and works
perfectly but I don’t know enough to be able to use it. Please will you
say more or direct me to some reference? I couldn’t find ‘nasty’ in the
Python docs.
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Re: String slices
On 2019-08-10 09:10:12 +1000, Cameron Simpson wrote:
> On 09Aug2019 22:28, Paul St George wrote:
> > On 09/08/2019 16:29, Rhodri James wrote:
> > > (Actually I would probably use outstream.write() and do my own
> > > formatting, but let's not get side-tracked ;-)
> > >
> > I would love to hear your outstream.write() side-track!
>
> I am not Rhodri James, but you can just write strings to text files:
>
> outstream.write("X: ") # note, includes the space separator
> outstream.write(str(thing[0]))
> outstring.write("\n")
You can also format the string before passing it to write (which is
probably what Rhodri meant by "do my own formatting", like this:
outstream.write("X: %7.2f\n" % thing[0])
or this
outstream.write("X: {0:7.2f}\n".format(thing[0]))
or (since Python 3.6) this:
outstream.write(f"X: {thing[0]:7.2f}\n")
There are of course many variants to all three methods.
hp
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|_|_) || because we have much more sophisticated
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Re: String slices
On 09Aug2019 22:28, Paul St George wrote:
On 09/08/2019 16:29, Rhodri James wrote:
The 'sep="\n"' parameter to print() means "put a newline between each
item." So don't do that. Put the newlines you do want in explicitly,
or use separate calls to print():
(I'm abbreviating because I really can't be bothered to type that
much :-)
print("X:", thing[0],
"\nY:", thing[1],
"\nZ:", thing[2],
file=outstream)
or
print("X:", thing[0], file=outstream)
print("Y:", thing[1], file=outstream)
print("Z:", thing[2], file=outstream)
I would probably use the latter, but it's just a matter of personal
preference.
(Actually I would probably use outstream.write() and do my own
formatting, but let's not get side-tracked ;-)
So, I am going with your second suggestion (see below) but I would love
to hear your outstream.write() side-track!
I am not Rhodri James, but you can just write strings to text files:
outstream.write("X: ") # note, includes the space separator
outstream.write(str(thing[0]))
outstring.write("\n")
print() is convenient, because it calls str() on any non-str argument
for you, and it does the space separators and newline line ending (both
overridable).
You can see the above is rather verbose. But it does let you control
exactly what gets written, _if_ the print separators and endings are
causing you inconvenience.
Personally, for text output, I use print unless there's some compelling
reason not to (such as transcribing a data structure precisely, not
wanting unexpected spaces and newlines; if I were hand transcribing JSON
or XML or HTML or the like).
Cheers,
Cameron Simpson
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Re: Re: String slices
On 09/08/2019 16:29, Rhodri James wrote:
On 09/08/2019 15:13, Paul St George wrote:
In the code (below) I want a new line like this:
Plane rotation X: 0.0
Plane rotation Y: 0.0
Plane rotation Z: 0.0
But not like this:
Plane rotation X:
0.0
Plane rotation Y:
0.0
Plane rotation Z:
0.0
Is it possible?
(I am using Python 3.5 within Blender.)
#
import os
outstream = open(os.path.splitext(bpy.data.filepath)[0] + ".txt",'w')
print(
"Plane rotation X:",bpy.data.objects["Plane"].rotation_euler[0],
"Plane rotation Y:",bpy.data.objects["Plane"].rotation_euler[1],
"Plane rotation Z:",bpy.data.objects["Plane"].rotation_euler[2],
file=outstream, sep="\n"
)
outstream.close()
The 'sep="\n"' parameter to print() means "put a newline between each
item." So don't do that. Put the newlines you do want in explicitly,
or use separate calls to print():
(I'm abbreviating because I really can't be bothered to type that much
:-)
print("X:", thing[0],
"\nY:", thing[1],
"\nZ:", thing[2],
file=outstream)
or
print("X:", thing[0], file=outstream)
print("Y:", thing[1], file=outstream)
print("Z:", thing[2], file=outstream)
I would probably use the latter, but it's just a matter of personal
preference.
(Actually I would probably use outstream.write() and do my own
formatting, but let's not get side-tracked ;-)
So, I am going with your second suggestion (see below) but I would love
to hear your outstream.write() side-track!
import os
with open(os.path.splitext(bpy.data.filepath)[0] + ".txt", "w") as outstream:
plane = bpy.data.objects["Plane"]
print("Plane rotation X:",plane.rotation_euler[0], file=outstream)
print("Plane rotation Y:",plane.rotation_euler[1], file=outstream)
print("Plane rotation Z:",plane.rotation_euler[2], file=outstream)
print("Focal length:", bpy.context.object.data.lens, file=outstream)
and so on...
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Re: String slices
Paul St George wrote:
> In the code (below) I want a new line like this:
>
> Plane rotation X: 0.0
> Plane rotation Y: 0.0
> Plane rotation Z: 0.0
>
> But not like this:
>
> Plane rotation X:
> 0.0
> Plane rotation Y:
> 0.0
> Plane rotation Z:
> 0.0
>
> Is it possible?
> print(
>
> "Plane rotation X:",bpy.data.objects["Plane"].rotation_euler[0],
>
> "Plane rotation Y:",bpy.data.objects["Plane"].rotation_euler[1],
>
> "Plane rotation Z:",bpy.data.objects["Plane"].rotation_euler[2],
>
> file=outstream, sep="\n"
>
> )
Explanation: The newlines between all positional args of print() are caused
by the sep="\n" keyword argument.
You probably got the idea from my
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"
)
in the other thread where I introduced the bug when trying to simplify my
original suggestion (which I didn't post)
print(
f"Plane rotation X: {x}",
f"Plane rotation Y: {y}",
f"Plane rotation Z: {z}",
file=outstream, sep="\n"
)
But as Dan says, use separate print() calls.
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Re: String slices
On 09/08/2019 15:13, Paul St George wrote:
In the code (below) I want a new line like this:
Plane rotation X: 0.0
Plane rotation Y: 0.0
Plane rotation Z: 0.0
But not like this:
Plane rotation X:
0.0
Plane rotation Y:
0.0
Plane rotation Z:
0.0
Is it possible?
(I am using Python 3.5 within Blender.)
#
import os
outstream = open(os.path.splitext(bpy.data.filepath)[0] + ".txt",'w')
print(
"Plane rotation X:",bpy.data.objects["Plane"].rotation_euler[0],
"Plane rotation Y:",bpy.data.objects["Plane"].rotation_euler[1],
"Plane rotation Z:",bpy.data.objects["Plane"].rotation_euler[2],
file=outstream, sep="\n"
)
outstream.close()
The 'sep="\n"' parameter to print() means "put a newline between each
item." So don't do that. Put the newlines you do want in explicitly,
or use separate calls to print():
(I'm abbreviating because I really can't be bothered to type that much :-)
print("X:", thing[0],
"\nY:", thing[1],
"\nZ:", thing[2],
file=outstream)
or
print("X:", thing[0], file=outstream)
print("Y:", thing[1], file=outstream)
print("Z:", thing[2], file=outstream)
I would probably use the latter, but it's just a matter of personal
preference.
(Actually I would probably use outstream.write() and do my own
formatting, but let's not get side-tracked ;-)
--
Rhodri James *-* Kynesim Ltd
--
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Re: String slices
On 8/9/19 10:13 AM, Paul St George wrote:
In the code (below) I want a new line like this:
Plane rotation X: 0.0
Plane rotation Y: 0.0
Plane rotation Z: 0.0
But not like this:
Plane rotation X:
0.0
Plane rotation Y:
0.0
Plane rotation Z:
0.0
Is it possible?
(I am using Python 3.5 within Blender.)
#
import os
outstream = open(os.path.splitext(bpy.data.filepath)[0] + ".txt",'w')
print(
"Plane rotation X:",bpy.data.objects["Plane"].rotation_euler[0],
"Plane rotation Y:",bpy.data.objects["Plane"].rotation_euler[1],
"Plane rotation Z:",bpy.data.objects["Plane"].rotation_euler[2],
file=outstream, sep="\n"
)
outstream.close()
Use separate calls to print:
with open(...) as outstream:
plane = bpy.data.objects["Plane"]
print("X:", plane.rotation_euler[0])
print("Y:", plane.rotation_euler[1])
# print Z here
And please (a) use "with" instead of "open" and "close," and
(b) use an email client that preserves indentation.
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RE: String slices work only for first string character ?
Thanks to all who pointed my wrong understanding of how string slices are defined. Bye, Ron. From: Barak, Ron [mailto:ron.ba...@lsi.com] Sent: Tuesday, December 16, 2008 15:35 To: python-list@python.org Subject: String slices work only for first string character ? Hi, Can any one explain why the following string slice works only for the first character, but not for any other ? $ cat /tmp/tmp.py #!/usr/bin/env python data = 'F0023209006-0101' print data print "|"+data[0:1]+"|" print "|"+data[1:1]+"|" print "|"+data[2:1]+"|" $ python `cygpath -w /tmp/tmp.py` F0023209006-0101 |F| || || $ Thanks, Ron. -- http://mail.python.org/mailman/listinfo/python-list
RE: String slices work only for first string character ?
Hi Mr. Cain, Mae culpa: obviously, I erroneously understood the number after the ':' as the string length. Thanks, Ron. -Original Message- From: D'Arcy J.M. Cain [mailto:da...@druid.net] Sent: Tuesday, December 16, 2008 15:45 To: Barak, Ron Cc: python-list@python.org Subject: Re: String slices work only for first string character ? On Tue, 16 Dec 2008 13:35:27 + "Barak, Ron" wrote: > Can any one explain why the following string slice works only for the first > character, but not for any other ? I think that you need to reread the docs on slices. > print "|"+data[0:1]+"|" > print "|"+data[1:1]+"|" If you want the second character use "data[1:2]". -- D'Arcy J.M. Cain | Democracy is three wolves http://www.druid.net/darcy/| and a sheep voting on +1 416 425 1212 (DoD#0082)(eNTP) | what's for dinner. -- http://mail.python.org/mailman/listinfo/python-list
Re: String slices work only for first string character ?
On Tue, 16 Dec 2008 13:35:27 + "Barak, Ron" wrote: > Can any one explain why the following string slice works only for the first > character, but not for any other ? I think that you need to reread the docs on slices. > print "|"+data[0:1]+"|" > print "|"+data[1:1]+"|" If you want the second character use "data[1:2]". -- D'Arcy J.M. Cain | Democracy is three wolves http://www.druid.net/darcy/| and a sheep voting on +1 416 425 1212 (DoD#0082)(eNTP) | what's for dinner. -- http://mail.python.org/mailman/listinfo/python-list
Re: String slices work only for first string character ?
Can any one explain why the following string slice works only for the first character, but not for any other ? $ cat /tmp/tmp.py #!/usr/bin/env python data = 'F0023209006-0101' print data print "|"+data[0:1]+"|" print "|"+data[1:1]+"|" print "|"+data[2:1]+"|" $ python `cygpath -w /tmp/tmp.py` F0023209006-0101 |F| || || Slices are defined by [start_idx:end_idx] not [start_idx:length] so you want data[0:1] data[1:2] data[2:3] -tkc -- http://mail.python.org/mailman/listinfo/python-list
