How to read from serial port?
Hi
I have written a very simple program to read and print data from the serial
port using pyserial:
#!/usr/bin/python3
import serial
ser=serial.Serial('COM1',115200)
while True:
out = ser.read()
print('Receiving...'+out)
When I run it and send data for it to read I get:
C:\SVNProj\Raggio\trunk\hostconsole\gui\prototypes\serial_test>py serial_read.py
Traceback (most recent call last):
File "serial_read.py", line 9, in
print('Receiving...'+out)
TypeError: Can't convert 'bytes' object to str implicitly
I am using Python 3.5. How would I fix this error please?
Best regards
David
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RE: Problem working with subprocess.check_call
> Try this > subprocess.check_call(["bash", "-O", "extglob", "-c", cmd]) That worked. Thanks very much! David -- https://mail.python.org/mailman/listinfo/python-list
Problem working with subprocess.check_call
Hi
I am working on Linux with Python 3.4.
I want to do a bash diff on two text files and show just the first 20 lines of
diff's output. So I tried:
>>> cmd = 'head -20 <(diff ' + file1 + ' ' + file2 + ')'
>>> subprocess.check_call(cmd, shell=True)
The command contained in cmd works ok from the bash prompt but not from Python
code. In Python I get:
/bin/sh: -c: line 0: syntax error near unexpected token `('
I think the problem is that check_call is not using the bash shell. So I also
tried:
>>> subprocess.check_call("bash", "-O", "extglob", "-c", cmd)
Traceback (most recent call last):
File "", line 1, in
File "/usr/local/lib/python3.4/subprocess.py", line 556, in check_call
retcode = call(*popenargs, **kwargs)
File "/usr/local/lib/python3.4/subprocess.py", line 537, in call
with Popen(*popenargs, **kwargs) as p:
File "/usr/local/lib/python3.4/subprocess.py", line 767, in __init__
raise TypeError("bufsize must be an integer")
TypeError: bufsize must be an integer
Can anyone help me with this please?
Best regards
David
--
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RE: Problem working with subprocess.check_call
Thanks for all your answers. David -- https://mail.python.org/mailman/listinfo/python-list
Automating Sphinx generated documentation
Hi I have setup Sphinx for my Python project. We keep all our code and documentation in Subversion. So, following changes to the Python code, I need to regenerate and commit the Sphinx generated documentation. I just wondered how people manage this. I'm thinking of using Jenkins (a continuous integration tool) to check for changes, regenerate the docs and check them in. Any suggestions please? Best regards David -- https://mail.python.org/mailman/listinfo/python-list
RE: kivy editable multicolumn list
> Not sure if this is the place to ask about kivy ... Try the kivy users list here: https://groups.google.com/forum/#!forum/kivy-users Best regards David -- https://mail.python.org/mailman/listinfo/python-list
A basic dictionary question
Hi
I am fairly new to Python. I am writing some code that uses a dictionary to
store definitions of hardware registers. Here is a small part of it:
import sys
register = {
'address' : 0x3001c,
'fields' : {
'FieldA' : {
'range' : (31,20),
},
'FieldB' : {
'range' : (19,16),
},
},
'width' : 32
};
def main():
fields = register['fields']
for field, range_dir in fields: == This line fails
range_dir = field['range']
x,y = range_dir['range']
print(x, y)
if __name__ == '__main__':
main()
I want the code to print the range of bits of each field defined in the
dictionary.
The output is:
Traceback (most recent call last):
File testdir.py, line 32, in module
main()
File testdir.py, line 26, in main
for field, range_dir in fields:
ValueError: too many values to unpack (expected 2)
Please will someone explain what I am doing wrong?
Also I would like to ask how I could print the ranges in the order they are
defined. Should I use a different dictionary class or could I add a field to
the dictionary/list to achieve this?
Best regards
David
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What sort of data structure to use?
Hi I have written a Python utility that performs a certain activity on some predefined sets of files. Here is the outline of what I have written: # File Set A pathA = 'pathA' fileListA = ['fileA1.txt', 'fileA2.txt'] # File Set B pathB = 'pathB' fileListB = ['fileB1.txt', 'fileB2.txt', 'fileB3.txt'] myFunc1(pathA, fileListA) myFunc2(pathA, fileListA) myFunc1(pathB, fileListB) myFunc2(pathB, fileListB) I want to add more file sets, so I really want to add the sets to a list and iterate over the list, calling myFunc1 myFunc2 for each item. My question is: what sort of data structure could I use to organise this, given that I want to associate a set of files with each path and that, for each set, there is an arbitrary number of files? Best regards David -- https://mail.python.org/mailman/listinfo/python-list
RE: What sort of data structure to use?
Thanks very much for all the answers given to my question. They help me to think about the problem pythonically. Best regards David -Original Message- From: Python-list [mailto:python-list- bounces+david.aldrich=emea.nec@python.org] On Behalf Of Peter Otten Sent: 03 June 2015 11:59 To: python-list@python.org Subject: Re: What sort of data structure to use? David Aldrich wrote: Hi I have written a Python utility that performs a certain activity on some predefined sets of files. Here is the outline of what I have written: # File Set A pathA = 'pathA' fileListA = ['fileA1.txt', 'fileA2.txt'] # File Set B pathB = 'pathB' fileListB = ['fileB1.txt', 'fileB2.txt', 'fileB3.txt'] myFunc1(pathA, fileListA) myFunc2(pathA, fileListA) myFunc1(pathB, fileListB) myFunc2(pathB, fileListB) I want to add more file sets, so I really want to add the sets to a list and iterate over the list, calling myFunc1 myFunc2 for each item. My question is: what sort of data structure could I use to organise this, given that I want to associate a set of files with each path and that, for each set, there is an arbitrary number of files? I'd start simple and put (path, files) pairs into a list: path_files_pairs = [ (pathA, [fileA1.txt, fileA2.txt, ...]), (pathB, [fileB1.txt, ...]), ] for path, files in path_files_pairs: func1(path, files) func2(path, files) You can always add complications later: import glob import os class VirtualFileset: def __init__(self, folder, pattern): self.folder = folder self.pattern = pattern def __iter__(self): yield self.folder yield glob.glob(os.path.join(self.folder, self.pattern)) path_files_pairs = [ (pathA, [fileA1.txt, fileA2.txt, ...]), (pathB, [fileB1.txt, ...]), VirtualFileset(pathC, *.py), # all python files in directory pathC ] for path, files in path_files_pairs: func1(path, files) func2(path, files) -- https://mail.python.org/mailman/listinfo/python-list Click https://www.mailcontrol.com/sr/51ZWmSF1P47GX2PQPOmvUmaGI8Tu3yGr Vrr5Tv1xM3UP2MNyoKSTyt0rIsjE4onM5MUvmWbo6fT3KeH4!zzvzA== to report this email as spam. -- https://mail.python.org/mailman/listinfo/python-list
Problem running Python 2.7 on Ubuntu 10.04
Hi I wonder if someone could help me with this problem please? On an Ubuntu 10.04 platform, I want to run the latest version of Meld, which is a Python program. Ubuntu 10.04 runs Python 2.6 as standard. Meld requires Python 2.7. So I have installed Python 2.7 under /usr/local/bin and Python 2.7 runs ok there. But when I try to run Meld I see: - /usr/local/bin/python2.7 ~/meld/bin/meld Cannot import: GTK+ No module named gi So I need to install the gtk package and do so in such a way that it is visible to /usr/local/bin/python2.7. How would I do that please? Best regards David Best regards David -- https://mail.python.org/mailman/listinfo/python-list
RE: Python shell: Arrow keys not working in PuTTY
BUT do *not* run `make install` as that will overwrite your system Python and Bad Things will happen. Instead, run `make altinstall`. Thanks for all the warnings. We did use `make altinstall`, so all is ok. Recompiling, with readline installed, fixed the arrow keys. -- https://mail.python.org/mailman/listinfo/python-list
Python shell: Arrow keys not working in PuTTY
Hi I want to use the Python 3.4 interpreter interactively, via a PuTTY ssh session. Python is running on Centos 5. Currently, the arrow keys do not work: $ /usr/local/bin/python3.4 Python 3.4.2 (default, Feb 11 2015, 15:06:33) [GCC 4.1.2 20080704 (Red Hat 4.1.2-55)] on linux Type help, copyright, credits or license for more information. ^[[A This stackoverflow thread: http://stackoverflow.com/questions/893053/python-shell-arrow-keys-do-not-work-on-remote-machine suggests that the problem can be fixed by installing the readline package: sudo apt-get install libreadline-dev followed by a rebuild of Python or pip install readline Please can anyone comment on the easiest way to fix this? Is a rebuild of Python necessary? Best regards David -- https://mail.python.org/mailman/listinfo/python-list
RE: Python shell: Arrow keys not working in PuTTY
Thanks for your replies, I will give readline a try. PS: and you mention being on CentOS but running apt-get. I believe CentOS and other Red-Hat based distros use yum instead of apt-get Yes, I think I need to use: yum install readline-devel Best regards David -- https://mail.python.org/mailman/listinfo/python-list
RE: A question about a list and subprocess.check_call()
It's also possible to do it the other around using shlex.split. I prefer that version because I can easily copy/paste the command from code to the shell, it's also more readable IMO: cmd = python3 -O -c import sys; print(sys.argv[1:]) foo bar spam egg print(cmd) subprocess.check_call(shlex.split(cmd)) Thanks again for the replies to my question. I especially like the solution of using shlex.split(). -- https://mail.python.org/mailman/listinfo/python-list
RE: A question about a list and subprocess.check_call()
Hi Peter
Thanks very much for your reply. I have added one more question below.
The straightforward approach is to pass a list or tuple:
def build(build_options=()):
subprocess_check_call((make,) + build_options)
build((flagA=true, flagB=true))
This looks fine - I am trying it.
I would like to display on the console the entire make command, so I have done
this:
def build(build_options=()):
make_command = 'make '.join(map(build_options))
print('Build command: ' + make_command)
subprocess.check_call((make,)+build_options)
but I get error:
make_command = 'make '.join(map(build_options))
TypeError: map() must have at least two arguments.
What would be the correct way to concatenate and display the elements in the
tuple please?
Best regards
David
--
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A question about a list and subprocess.check_call()
Hi
I wonder if someone could help me with this problem please. I am writing a
Python script that builds and tests a C++ program on Linux. The build options
depend on the test, so I have encapsulated the 'make' call in a Python function:
def build(build_options=''):
if len(build_options):
subprocess.check_call(['make',build_options])
else:
subprocess.check_call('make')
This works fine if I call:
build()
or
build('flagA=true')
The latter gives:
make flagA=true
which is correct.
However, I now want to call make with two flags:
make flagA=true flagB=true
I tried calling:
build('flagA=true flagB=true')
which did indeed result in:
make flagA=true flagB=true
but 'make' ignored the second option. So I think that the list that was passed
to subprocess.check_call() was incorrect.
In summary, I want to pass a list to build(), which by default should be empty,
and pass that list on to subprocess.check_call() with 'make' as the first
element of the list.
Any ideas please?
Best regards
David
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Beginner question - class definition error
Hi
I am just getting started with Python 3.3.3 and Kivy 1.8.
I am using the Kivy development environment on Windows (open a command prompt
and call kivy.bat).
With this minimal code:
import kivy
kivy.require('1.8.0')
from kivy.app import App
from kivy.uix.label import Label
class MyApp(App):
def build(self):
return Label(text='Hello World')
if __name__ == '__main__':
MyApp().run()
I get this error when I run it:
C:\python MinimalApplication.py
[INFO ] Kivy v1.8.0
[INFO ] [Logger ] Record log in snip
[INFO ] [Factory ] 157 symbols loaded
[DEBUG ] [Cache ] register kv.lang with limit=None,
timeout=Nones
[DEBUG ] [Cache ] register kv.image with limit=None,
timeout=60s
[DEBUG ] [Cache ] register kv.atlas with limit=None,
timeout=Nones
[INFO ] [Image ] Providers: img_tex, img_dds, img_pygame,
img_gif (img_pil ignored)
[DEBUG ] [Cache ] register kv.texture with limit=1000,
timeout=60s
[DEBUG ] [Cache ] register kv.shader with limit=1000,
timeout=3600s
[INFO ] [Text] Provider: pygame
Traceback (most recent call last):
File MinimalApplication.py, line 7, in module
class MyApp(App):
File MinimalApplication.py, line 12, in MyApp
MyApp().run()
NameError: name 'MyApp' is not defined
How can I fix this please?
Best regards
David
--
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RE: Beginner question - class definition error
Unindent the 'if' statement. Currently, it's indented inside the class definition, so MyApp isn't defined yet. Thanks very much. That fixed it. Best regards David -- https://mail.python.org/mailman/listinfo/python-list
A question about setup.py
Hi I'm trying to install the path.py package under Python 2.7 on Windows. I installed it using: easy_install path.py That worked but it didn't install path.py which is needed by my PTVS IDE for code completion (Intellisense). I then tried downloading path.py-7.0.zip. I unzipped it and ran: python setup.py install within the extracted folder. But path.py still appears not to have been copied to: C:\Python27 What am I doing wrong? Best regards David -- https://mail.python.org/mailman/listinfo/python-list
Where is path.py?
Hi I am running Python 2.7 on Windows 8.1. Today I installed path.py using easy_install: easy_install path.py The example code that I've seen imports path.py as follows: from path import path I am fairly new to Python and have a few questions about this: 1) Why is 'from path' required here? 2) I am using Microsoft's PTVS IDE to develop my code. It is not displaying code completion for path.py (it works for the standard libraries). How would I tell PTVS about path.py? Perhaps I just need to know where path.py is as I can't find it in my filesystem. Best regards David -- https://mail.python.org/mailman/listinfo/python-list
RE: Where is path.py?
The syntax: from module import name will import the name name from the module module, so: from path import path will import the name 'path' (a class) from the module 'path'. Thanks. But I don't quite understand. If I use sys: import sys args = sys.argv[1:] I don't need to use 'from'. What is different with using path? Perhaps I just need to know where path.py is as I can't find it in my filesystem. Try: import path print path.__file__ c:\Python27\lib\site-packages\path.py-7.0-py2.7.egg\path.pyc Where would I typically put that path in an IDE? Thanks for your help. David -- https://mail.python.org/mailman/listinfo/python-list
RE: Where is path.py?
The only confusing bit here is that instead of sys and argv, you have path and path, the same name twice. But it's the same thing happening. Thanks very much for all replies I received for my question. It's clearer now. By the way, for Windows users, I do recommend Microsoft's PTVS (Python Tools for Visual Studio). It's an excellent IDE and free if you use the Express Edition of Visual Studio. David -- https://mail.python.org/mailman/listinfo/python-list
Missing python27.dll on Win 7 64-bit
Hi I am building a 32-bit C++ application using Visual C++ Express 2008 on 64-bit Windows 7. The application links to Python, so I installed 32-bit Python 2.7.2 by running python-2.7.2.msi. When I run my app, I get error: ... python27.dll is missing from your computer ... and, indeed, it is in neither C:\Windows\System32 nor C:\Windows\SysWOW64. Please will someone suggest what I am doing wrong? Best regards David -- http://mail.python.org/mailman/listinfo/python-list
Missing python27.dll on Win 7 64-bit
Hi I am building a 32-bit C++ application using Visual C++ Express 2008 on 64-bit Windows 7. The application links to Python, so I installed 32-bit Python 2.7.2 by running python-2.7.2.msi. When I run my app, I get error: ... python27.dll is missing from your computer ... and, indeed, it is in neither C:\Windows\System32 nor C:\Windows\SysWOW64. Please will someone suggest what I am doing wrong? Best regards David -- http://mail.python.org/mailman/listinfo/python-list
