[Solved] Re: Windows registry PermissionError
Eryk
Many thanks. It is working perfectly now. See below for the reworked code.
Cheers
Mike
On 13/05/2022 1:42 pm, Eryk Sun wrote:
On 5/12/22, Mike Dewhirst wrote:
access=wr.KEY_ALL_ACCESS + wr.KEY_WRITE,
import winreg as wr class Registry: def __init__(self, computer=None,
hkey=None, sub_key=None): self.computer = computer self.key = hkey
self.sub_key = sub_key def connect(self): return
wr.ConnectRegistry(self.computer, self.key) def select(self,
access=None): with self.connect() as hkey: return wr.OpenKeyEx(key=hkey,
sub_key=self.sub_key, access=access) def count(self): access =
wr.KEY_QUERY_VALUE return wr.QueryInfoKey(self.select(access=access))
def query(self, vname, access=None): if access is None: access =
wr.KEY_READ | wr.KEY_WOW64_32KEY return
wr.QueryValueEx(self.select(access=access), vname) def setvalue(self,
vname, value, access=None): if access is None: access = wr.KEY_SET_VALUE
with self.select(access=access) as hkey: return wr.SetValueEx(hkey,
vname, 0, wr.REG_SZ, value) if __name__ == "__main__": lmregistry =
Registry( hkey=wr.HKEY_LOCAL_MACHINE, sub_key=r"SOFTWARE\XXX
Technology\AppName", ) print(f"\n{lmregistry.sub_key}") anz =
lmregistry.query('Country')[0] print(f"\n{anz}") db =
lmregistry.query('Database')[0] print(f"\n{db}") devref =
lmregistry.query('v135')[0] print(f"\n{devref}") orgid =
lmregistry.query('v136')[0] print(f"\n{orgid}") curegistry = Registry(
hkey=wr.HKEY_CURRENT_USER, sub_key=r"SOFTWARE\XXX Technology\AppName", )
print(f"\n{curegistry.sub_key}") anz = curegistry.query('Country')[0]
print(f"\n{anz}") db = curegistry.query('Database')[0] print(f"\n{db}")
devref = curegistry.query('v135')[0] print(f"\n{devref}") orgid =
curegistry.query('v136')[0] print(f"\n{orgid}")
curegistry.setvalue('Country', 'nz') curegistry.setvalue('Database',
'2022.2') curegistry.setvalue('v135', 'Asus10')
curegistry.setvalue('v136', orgid.replace('ALL', 'Most')) anz =
curegistry.query('Country')[0] print(f"\n{anz}") db =
curegistry.query('Database')[0] print(f"\n{db}") devref =
curegistry.query('v135')[0] print(f"\n{devref}") orgid =
curegistry.query('v136')[0] print(f"\n{orgid}")
Again, many thanks for putting so much effort into educating me.
Cheers
Mike
The access parameter is a bit mask of access rights that combine via
bitwise OR (|), not via arithmetic addition.
KEY_ALL_ACCESS (0x000F_003F) is a superset of KEY_WRITE (0x0002_0006):
KEY_WRITE = (
READ_CONTROL | # 0x0002_
KEY_SET_VALUE | # 0x_0002
KEY_CREATE_SUB_KEY | # 0x_0004
)# 0x0002_0006
KEY_ALL_ACCESS = (
DELETE | # 0x0001_
READ_CONTROL | # 0x0002_
WRITE_DAC | # 0x0004_
WRITE_OWNER| # 0x0008_
KEY_QUERY_VALUE| # 0x_0001
KEY_SET_VALUE | # 0x_0002
KEY_CREATE_SUB_KEY | # 0x_0004
KEY_ENUMERATE_SUB_KEYS | # 0x_0008
KEY_NOTIFY | # 0x_0010
KEY_CREATE_LINK| # 0x_0020
)# 0x000F_003F
The result of the arithmetic addition `KEY_ALL_ACCESS + KEY_WRITE` is
0x0011_0045, which is wrong and meaningless. Registry key objects do
not support SYNCHRONIZE (0x0010_) access; DELETE (0x0001_)
access isn't needed; 0x_0040 is not a supported key right;
KEY_CREATE_SUB_KEY (0x_0004) access isn't needed; and
KEY_QUERY_VALUE (0x_0001) isn't sufficient.
You should limit the requested access to the specific access rights
that are required for querying and setting values in the key:
access=(wr.KEY_QUERY_VALUE | wr.KEY_SET_VALUE)
def setvalue(self, vname, value):
return wr.SetValueEx(self.select(), vname, 0, 1, value)
You shouldn't hard code the value of the data type constant. Use
wr.REG_SZ instead of 1.
The return value of self.select() is a winreg PyHKEY object that wraps
the OS handle for the key object. You're relying on implicit closing
of this handle based on referencing counting. It's cleaner to use it
in a `with` statement, as you would for a file object returned by
open(). For example:
with self.select() as hkey:
wr.SetValueEx(hkey, vname, 0, wr.REG_SZ, value)
lmregistry = Registry(
hkey=wr.HKEY_LOCAL_MACHINE,
sub_key="SOFTWARE\WOW6432Node\XXX Technology\AppName",
You really shouldn't open the "WOW6432Node" key directly. It is an
implementation detail of the WOW64 subsystem that runs 32-bit
applications on a 64-bit system. If you need to operate on the
registry keys of 32-bit applications from a native 64-bit process,
open the normal path using the access right KEY_WOW64_32KEY
(0x_0200). For example:
hkey = wr.HKEY_LOCAL_MACHINE
subkey = r"SOFTWARE\XXX Technology\AppName"
access = (
wr.KEY_QUERY_VALUE |
Re: Windows registry PermissionError
On 5/12/22, Mike Dewhirst wrote: > > access=wr.KEY_ALL_ACCESS + wr.KEY_WRITE, The access parameter is a bit mask of access rights that combine via bitwise OR (|), not via arithmetic addition. KEY_ALL_ACCESS (0x000F_003F) is a superset of KEY_WRITE (0x0002_0006): KEY_WRITE = ( READ_CONTROL | # 0x0002_ KEY_SET_VALUE | # 0x_0002 KEY_CREATE_SUB_KEY | # 0x_0004 )# 0x0002_0006 KEY_ALL_ACCESS = ( DELETE | # 0x0001_ READ_CONTROL | # 0x0002_ WRITE_DAC | # 0x0004_ WRITE_OWNER| # 0x0008_ KEY_QUERY_VALUE| # 0x_0001 KEY_SET_VALUE | # 0x_0002 KEY_CREATE_SUB_KEY | # 0x_0004 KEY_ENUMERATE_SUB_KEYS | # 0x_0008 KEY_NOTIFY | # 0x_0010 KEY_CREATE_LINK| # 0x_0020 )# 0x000F_003F The result of the arithmetic addition `KEY_ALL_ACCESS + KEY_WRITE` is 0x0011_0045, which is wrong and meaningless. Registry key objects do not support SYNCHRONIZE (0x0010_) access; DELETE (0x0001_) access isn't needed; 0x_0040 is not a supported key right; KEY_CREATE_SUB_KEY (0x_0004) access isn't needed; and KEY_QUERY_VALUE (0x_0001) isn't sufficient. You should limit the requested access to the specific access rights that are required for querying and setting values in the key: access=(wr.KEY_QUERY_VALUE | wr.KEY_SET_VALUE) > def setvalue(self, vname, value): >return wr.SetValueEx(self.select(), vname, 0, 1, value) You shouldn't hard code the value of the data type constant. Use wr.REG_SZ instead of 1. The return value of self.select() is a winreg PyHKEY object that wraps the OS handle for the key object. You're relying on implicit closing of this handle based on referencing counting. It's cleaner to use it in a `with` statement, as you would for a file object returned by open(). For example: with self.select() as hkey: wr.SetValueEx(hkey, vname, 0, wr.REG_SZ, value) > lmregistry = Registry( > hkey=wr.HKEY_LOCAL_MACHINE, > sub_key="SOFTWARE\WOW6432Node\XXX Technology\AppName", You really shouldn't open the "WOW6432Node" key directly. It is an implementation detail of the WOW64 subsystem that runs 32-bit applications on a 64-bit system. If you need to operate on the registry keys of 32-bit applications from a native 64-bit process, open the normal path using the access right KEY_WOW64_32KEY (0x_0200). For example: hkey = wr.HKEY_LOCAL_MACHINE subkey = r"SOFTWARE\XXX Technology\AppName" access = ( wr.KEY_QUERY_VALUE | wr.KEY_SET_VALUE | wr.KEY_WOW64_32KEY ) Typically you'd first try opening the path without either KEY_WOW64_32KEY or KEY_WOW64_64KEY. The default view matches the current process. https://docs.microsoft.com/en-us/windows/win32/winprog64/accessing-an-alternate-registry-view Remember to escape the backslash separators in string literals of key paths, or use raw string literals as I used in the above example. -- https://mail.python.org/mailman/listinfo/python-list
Windows registry PermissionError
I'm trying to copy a value from HKLM to HKCU for application rollout via
bulk installation by an administrator but individual Windows user setup.
Getting this ...
Traceback (most recent call last):
File "D:\Users\mike\envs\chemdata\registry\wreg\wreg.py", line 84, in
curegistry.setvalue('Country', anz)
File "D:\Users\mike\envs\chemdata\registry\wreg\wreg.py", line 51, in
setvalue
return wr.SetValueEx(self.select(), vname, 0, 1, value)
PermissionError: [WinError 5] Access is denied
... on my very own laptop where my login has admistrator permissions ...
which I realise means nothing in this case.
But I would not have been surprised if it worked here but not in the
field where users are firefighters and definitely not administrators and
cannot install software on their workstations.
import winreg as wr
class Registry:
def __init__(self, computer=None, hkey=None, sub_key=None):
# computer is None means this computer
self.computer = computer
self.key = hkey
self.sub_key = sub_key
def connect(self):
return wr.ConnectRegistry(self.computer, self.key)
def select(self):
# also tried OpenKeyEx()
return wr.OpenKey(
key=self.key,
sub_key=self.sub_key,
access=wr.KEY_ALL_ACCESS + wr.KEY_WRITE,
)
def query(self, vname):
return wr.QueryValueEx(self.select(), vname)
def setvalue(self, vname, value):
return wr.SetValueEx(self.select(), vname, 0, 1, value)
if __name__ == "__main__":
lmregistry = Registry(
hkey=wr.HKEY_LOCAL_MACHINE,
sub_key="SOFTWARE\WOW6432Node\XXX Technology\AppName",
)
print(f"\n{lmregistry.sub_key}")
anz = lmregistry.query('Country')[0]
print(f"\n{anz}") # works fine
curegistry = Registry(
hkey=wr.HKEY_CURRENT_USER,
sub_key="SOFTWARE\XXX Technology\AppName",
)
curegistry.setvalue('Country', anz) < BOOM <
...
Any hints appreciated.
Cheers
Mike
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Accuracy of multiprocessing.Queue.qsize before any Queue.get invocations?
The documentation says[1] > Return the approximate size of the queue. Because of > multithreading/multiprocessing semantics, this number is not > reliable. Are there any circumstances under which it *is* reliable? Most germane, if I've added a bunch of items to the Queue, but not yet launched any processes removing those items from the Queue, does Queue.qsize accurately (and reliably) reflect the number of items in the queue? q = Queue() for fname in os.listdir(): q.put(fname) file_count = q.qsize() # is this reliable? # since this hasn't yet started fiddling with it for _ in range(os.cpu_count()): Process(target=myfunc, args=(q, arg2, arg3)).start() I'm currently tracking the count as I add them to my Queue, file_count = 0 for fname in os.listdir(): q.put(fname) file_count += 1 but if .qsize is reliably accurate before anything has a chance to .get data from it, I'd prefer to tidy the code by removing the redunant counting code if I can. I'm just not sure what circumstances the "this number is not reliable" holds. I get that things might be asynchronously added/removed once processes are running, but is there anything that would cause unreliability *before* other processes/consumers run? Thanks, -tkc [1] https://docs.python.org/3/library/multiprocessing.html#multiprocessing.Queue.qsize -- https://mail.python.org/mailman/listinfo/python-list
Re: tail
On 12May2022 19:48, Marco Sulla wrote: >On Thu, 12 May 2022 at 00:50, Stefan Ram wrote: >> There's no spec/doc, so one can't even test it. > >Excuse me, you're very right. > >""" >A function that "tails" the file. If you don't know what that means, >google "man tail" > >filepath: the file path of the file to be "tailed" >n: the numbers of lines "tailed" >chunk_size: oh don't care, use it as is This is nearly the worst "specification" I have ever seen. Describe what your function _does_. Do not just send people to an arbitrary search engine to find possibly ephemeral web pages where someone has typed "man tail" and/or (if lucky) web pages with the output of "man tail" for any of several platforms. But this is sounding more and more like a special purpose task to be done for your particular use cases. That says it should be in your personal toolkit. If it has general applicability, _publish_ your toolkit for others to use. You can do that trivially by pushing your code repo to any of several free services like bitbucket, gitlab, sourcehut, github etc. Or you can go the extra few yards and publish a package to PyPI and see if anyone uses it. Part of your problem is that you think the term "tail" has a specific simple obvious meaning. But even to me it means at least 2 things: - to report the last "n" "lines" of a text file - to continuously report "new" data appended to a file These are different, though related, tasks. The latter one is particularly easy if done purely for bytes (on systems which allow it). As you've had explained to you, the former task is actually very fiddly. It is fiddly both in boundary conditions and complicated by being dependent on the text encoding, which you do not inherently know - that implies that you ought to (a) provide a way to specify that encoding and (b) maybe have a reasonable fallback default. But that default needs to be carefully and precisely explained. And the "find a line ending" criteria need to be explained. And the "sync to a character boundary" needs to be explained, including where it cannot be done. Cheers, Cameron Simpson -- https://mail.python.org/mailman/listinfo/python-list
Re: tail
On Thu, 12 May 2022 22:45:42 +0200, Marco Sulla declaimed the following: > >Maybe. Maybe not. What if the file ends with no newline? https://github.com/coreutils/coreutils/blob/master/src/tail.c Lines 567-569 (also lines 550-557 for "bytes_read" determination) -- Wulfraed Dennis Lee Bieber AF6VN wlfr...@ix.netcom.comhttp://wlfraed.microdiversity.freeddns.org/ -- https://mail.python.org/mailman/listinfo/python-list
Re: tail
Thank you very much. This helped me to improve the function: import os _lf = b"\n" _err_n = "Parameter n must be a positive integer number" _err_chunk_size = "Parameter chunk_size must be a positive integer number" def tail(filepath, n=10, chunk_size=100): if (n <= 0): raise ValueError(_err_n) if (n % 1 != 0): raise ValueError(_err_n) if (chunk_size <= 0): raise ValueError(_err_chunk_size) if (chunk_size % 1 != 0): raise ValueError(_err_chunk_size) n_chunk_size = n * chunk_size pos = os.stat(filepath).st_size chunk_line_pos = -1 newlines_to_find = n first_step = True with open(filepath, "rb") as f: text = bytearray() while pos != 0: pos -= n_chunk_size if pos < 0: pos = 0 f.seek(pos) chars = f.read(n_chunk_size) text[0:0] = chars search_pos = n_chunk_size while search_pos != -1: chunk_line_pos = chars.rfind(_lf, 0, search_pos) if first_step and chunk_line_pos == search_pos - 1: newlines_to_find += 1 first_step = False if chunk_line_pos != -1: newlines_to_find -= 1 if newlines_to_find == 0: break search_pos = chunk_line_pos if newlines_to_find == 0: break return bytes(text[chunk_line_pos+1:]) On Thu, 12 May 2022 at 20:29, Stefan Ram wrote: > I am not aware of a definition of "line" above, > but the PLR says: > > |A physical line is a sequence of characters terminated > |by an end-of-line sequence. > > . So 10 lines should have 10 end-of-line sequences. > Maybe. Maybe not. What if the file ends with no newline? -- https://mail.python.org/mailman/listinfo/python-list
Re: Changing calling sequence
On 11/05/2022 14.58, anthony.flury wrote: Why not do : def TempsOneDayDT(date:datetime.date): return TempsOneDay(date.year, date.month, date.day) No repeat of code - just a different interface to the same functionality. Yeah, a one-line wrapper around the original function seems a lot simpler that any of my ideas. I think that I'll even use the name from your example. Thanks to all who posted, as well as the many lurkers who support me in email. -- Michael F. Stemper Economists have correctly predicted seven of the last three recessions. -- https://mail.python.org/mailman/listinfo/python-list
Re: "py" command for Linux and Mac?
On 2022-05-12, Mats Wichmann wrote: > On 5/12/22 10:25, Dan Stromberg wrote: >> Hi folks. >> >> I heard there's a Windows-like "py" command for Linux (and Mac?). >> >> I'm finally getting to porting a particular project's Python 2.7 code to >> 3.x, and one of the first steps will probably be changing a lot of "python2 >> script.py" to use #!/usr/bin/env python2 and chmod +x. Then we can update >> the scripts one at a time to use #!/usr/bin/env python3. >> >> However, would this be Linux-and-Mac-only? I'm not at all sure this code >> will ever move to Windows, but in case it does, would a "py" command work >> on all 3 if I use #!/usr/bin/env py? > > The py command (python lanucher) respects shebang lines. Linux by itself respects shebang lines, so you don't need a separate launcher program. Just put e.g.: #! /usr/bin/env python at the top of your Python file. -- In the beginning there was darkness and the darkness was without form and void. And in addition to the darkness there was also me. And I moved upon the face of the darkness and I saw that I was alone. ... ... ... Let there be light. [Bomb 20; John Carpenter's Dark Star - 1974] -- https://mail.python.org/mailman/listinfo/python-list
Re: "py" command for Linux and Mac?
On 5/12/22 10:25, Dan Stromberg wrote: > Hi folks. > > I heard there's a Windows-like "py" command for Linux (and Mac?). > > I'm finally getting to porting a particular project's Python 2.7 code to > 3.x, and one of the first steps will probably be changing a lot of "python2 > script.py" to use #!/usr/bin/env python2 and chmod +x. Then we can update > the scripts one at a time to use #!/usr/bin/env python3. > > However, would this be Linux-and-Mac-only? I'm not at all sure this code > will ever move to Windows, but in case it does, would a "py" command work > on all 3 if I use #!/usr/bin/env py? The py command (python lanucher) respects shebang lines. https://docs.python.org/3/using/windows.html#python-launcher-for-windows -- https://mail.python.org/mailman/listinfo/python-list
Re: tail
On Thu, 12 May 2022 at 00:50, Stefan Ram wrote: > > Marco Sulla writes: > >def tail(filepath, n=10, chunk_size=100): > >if (n <= 0): > >raise ValueError(_err_n) > ... > > There's no spec/doc, so one can't even test it. Excuse me, you're very right. """ A function that "tails" the file. If you don't know what that means, google "man tail" filepath: the file path of the file to be "tailed" n: the numbers of lines "tailed" chunk_size: oh don't care, use it as is """ -- https://mail.python.org/mailman/listinfo/python-list
Re: "py" command for Linux and Mac?
On 2022-05-12 17:25, Dan Stromberg wrote: Hi folks. I heard there's a Windows-like "py" command for Linux (and Mac?). I'm finally getting to porting a particular project's Python 2.7 code to 3.x, and one of the first steps will probably be changing a lot of "python2 script.py" to use #!/usr/bin/env python2 and chmod +x. Then we can update the scripts one at a time to use #!/usr/bin/env python3. However, would this be Linux-and-Mac-only? I'm not at all sure this code will ever move to Windows, but in case it does, would a "py" command work on all 3 if I use #!/usr/bin/env py? And if so, where can I find that "py" command for Linux and Mac? I tried searching for it in Google and on Pypi, but unsurprisingly searching for "py" gives a buzzillion hits on other things. It's called the "Python Launcher"; you'll get more helpful results if you search for that. -- https://mail.python.org/mailman/listinfo/python-list
"py" command for Linux and Mac?
Hi folks. I heard there's a Windows-like "py" command for Linux (and Mac?). I'm finally getting to porting a particular project's Python 2.7 code to 3.x, and one of the first steps will probably be changing a lot of "python2 script.py" to use #!/usr/bin/env python2 and chmod +x. Then we can update the scripts one at a time to use #!/usr/bin/env python3. However, would this be Linux-and-Mac-only? I'm not at all sure this code will ever move to Windows, but in case it does, would a "py" command work on all 3 if I use #!/usr/bin/env py? And if so, where can I find that "py" command for Linux and Mac? I tried searching for it in Google and on Pypi, but unsurprisingly searching for "py" gives a buzzillion hits on other things. Thanks! -- https://mail.python.org/mailman/listinfo/python-list
RE: Changing calling sequence
>>def TempsOneDay(*dateComponents):
>>if len(dateComponents) == 3:
>>year, month, date = dateComponents
>>elif len(dateComponents) == 1 and isinstance(dateComponents[0],
>> datetime.date):
>>year, month, date = (dateComponents[0].year, dateComponents[0].month,
>> dateComponents[0].day)
>>else:
>>raise Exception("Error message here")
>
>|>>> help( TempsOneDay )
>|Help on function TempsOneDay in module __main__:
>|
>|TempsOneDay(*dateComponents)
Then just add an appropriate docstring.
>>> def TempsOneDay(*dateComponents):
... """Can be called either with 3 arguments: year, month, day
...or with a single datetime.date object"""
... if len(dateComponents) == 3:
... year, month, date = dateComponents
... elif len(dateComponents) == 1 and isinstance(dateComponents[0],
datetime.date):
... year, month, date = (dateComponents[0].year,
dateComponents[0].month, dateComponents[0].day)
... else:
... raise Exception("Error message here")
...
>>> help(TempsOneDay)
Help on function TempsOneDay in module __main__:
TempsOneDay(*dateComponents)
Can be called either with 3 arguments: year, month, day
or with a single datetime.date object
>>>
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[Python-announce] ANN: poliastro 0.16.3 released
Hi all, It fills us with astronomical joy to announce the release of poliastro 0.16.3! poliastro is an open source (MIT) pure Python library for interactive Astrodynamics and Orbital Mechanics, with a focus on ease of use, speed, and quick visualization. It provides a simple and intuitive API, and handles physical quantities with units. It is used in academia and the industry by people from all around the world. You can install it using pip or conda: pip install poliastro conda install poliastro --channel conda-forge This small release fixes some problems with latest Astropy on Python 3.10, and help us prepare for the upcoming SciPy 2022 conference in Austin, Texas, USA. You can read the full release notes here: https://docs.poliastro.space/en/v0.16.3/changelog.html#poliastro-0-16-3- 2022-05-09 If you want to learn more about poliastro, don't miss my talk on the Open Source Cubesat Workshop held at the European Space Operations Centre in 2017: https://youtu.be/KnoYzqAw_vM?t=1h36m14s And feel welcome to join our chat on Matrix to ask any questions you might have and participate in our weekly community meetings: http://chat.poliastro.space Per Python ad astra! --- Juan Luis Cano Rodríguez ___ Python-announce-list mailing list -- python-announce-list@python.org To unsubscribe send an email to python-announce-list-le...@python.org https://mail.python.org/mailman3/lists/python-announce-list.python.org/ Member address: arch...@mail-archive.com
Re: [docs] Reporting a Bug
This is exactly as expected.
Strip removes any of the characters in the passed string from both the
front and the end of the string being stripped.
The letter 'T' from the start of 'The meaning of life' does not appear
in the word 'meaning' so nothing is removed from the start of the
string.
The letter 'e' from the end of 'The meaning of life' does appear in the
word 'meaning' so it is removed from the sentence; it will then look at
the next last letter 'f', but since this doesn't appear in the word
'meaning' nothing else is removed and the new string is returned.
The argument passed to strip(..) method is the set of characters to be
removed - so any characters in that set are removed from the start and
end of the string.
-- Original Message --
From: "Jeff Jeffi"
To: d...@python.org
Cc: python-list@python.org
Sent: Wednesday, 4 May, 22 At 10:36
Subject: [docs] Reporting a Bug
Hello dears,
First of all i am not sure about this issue please advise me if
there is any mistake in my report.
for example in python 3.6.3 shell:
x= "The meaning of life" x.strip("meaning")
'The meaning of lif'
As you see the letter "e" of the word "life" is removed.
Sincerely yours.
J.Mohammadi
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Re: [Python-ideas] Re: New Tool Proposal
On 10/05/2022 15:04, Dan Stromberg wrote: On Tue, May 10, 2022 at 3:15 AM Chris Angelico wrote: > It is often the case that developer write Code in Python and then convert to a C extension module for performance regions. > > A C extension module has a lot of boiler plate code - for instance the Structures required for each class, the functions for Module initialization etc. > > My Idea is a simple tool that uses introspection tools to take a Python module and to generate the relevant boiler plate for the module - including blank functions for the module classes and for methods. This tool would use type annotations (if given) to make sensible choices for parameter and attribute types, including using int and float directly rather than Internal objects (depending on tool options). Two things to say about this: 1) Sometimes abandoning a pure python module for a C extension for performance is a mistake - because Pypy is probably going to be much faster with the pure python module Dan, Thanks for your response, but I think PyPy will have a long way to go to make JIT generated code more efficient than hand crafted C extension. for instance PyPy will almost certainly be unable to determine if integers, floats etc will need to use the Python runtime or can be optimized to use direct C types, another example would be lists - there are some cases where the C extension will always be a lot more efficient using C arrays than using the C list runtime machinery. While there might be some cases where PyPy will be more efficient, I don't think that will be the case for all programs, and that ignores the fact that PyPi has major issues with the CAPI. 2) I've had some luck using m4 to maintain a single source file that is used to automatically generate both pure python and cython. This is a little like using cpp in a C project. For examples of #2, perhaps see: https://stromberg.dnsalias.org/~strombrg/treap/ https://stromberg.dnsalias.org/svn/rolling_checksum_mod/trunk/ https://stromberg.dnsalias.org/~strombrg/sort-comparison/ It's often nice to keep the lines of the pure-python and cython having a 1-1 relationship, so that tracebacks report useful line numbers either way. However, in the treap example I've dispensed with that because some methods were almost identical but had some boilerplate - and m4 was able to handle that nicely at the cost of lines being 1-1. HTH -- Anthony Flury *Moble*: +44 07743 282707 *Home*: +44 (0)1206 391294 *email*: anthony.fl...@btinternet.com -- https://mail.python.org/mailman/listinfo/python-list
