Python - Revision history

Steffe at 09:30, 14 October 2024

2024-10-14T09:30:35Z

← Older revision		Revision as of 09:30, 14 October 2024
Line 4:		Line 4:

	Note however that threading in python is limited due to the GIL. To achieve "true" threading, use the "[https://docs.python.org/2/library/multiprocessing.html multiprocess]" library (which in fact spawns different processes and uses IPC mechanism for communication etc): https://www.quantstart.com/articles/Parallelising-Python-with-Threading-and-Multiprocessing		Note however that threading in python is limited due to the GIL. To achieve "true" threading, use the "[https://docs.python.org/2/library/multiprocessing.html multiprocess]" library (which in fact spawns different processes and uses IPC mechanism for communication etc): https://www.quantstart.com/articles/Parallelising-Python-with-Threading-and-Multiprocessing

			== Debugging ==

			Python can be debugged using rpdb2: https://pypi.org/project/rpdb2/

			Since it is not distributed with any major distributions, you have to install it using pip, preferably in a virtual environment:

			mkdir ~/pyenv
			mkdir ~/pyenv/rpdb2
			python -m venv pyenv/rpdb2/
			~/pyenv/rpdb2/bin/pip install rpdb2

			Now you need to hook into rpdb2 from the python program that you want to debug. Add this line to the python code:

			import rpdb2; rpdb2.start_embedded_debugger("pass")

			The string "pass" is the password to connect from the debugger. Now start your application (using the same virtual environment so that you can access the rpdb2 library):

			~/pyenv/rpdb2/bin/python <yourapplication.py>

			It will halt at startup and wait for debugger to connect. In another terminal, launch the debugger:

			~/pyenv/rpdb2/bin/python -m rpdb2

			Now issue the following commands to attach to your process and run it:

			password pass
			attach
			go

			Now you can issue command "help" to get more info. Commands such as "thread" and "stack" might be helpful.

	== Tkinter and simple GUI programming ==		== Tkinter and simple GUI programming ==

Stefan: /* Threading */

2018-06-18T09:25:46Z

Threading

← Older revision		Revision as of 09:25, 18 June 2018
Line 3:		Line 3:
	http://www.tutorialspoint.com/python/python_multithreading.htm		http://www.tutorialspoint.com/python/python_multithreading.htm

	Note however that threading in python is limited due to the GIL. To achieve "true" threading, use the "multiprocess" library (which in fact spawns different processes and uses IPC mechanism for communication etc):		Note however that threading in python is limited due to the GIL. To achieve "true" threading, use the "[https://docs.python.org/2/library/multiprocessing.html multiprocess]" library (which in fact spawns different processes and uses IPC mechanism for communication etc): https://www.quantstart.com/articles/Parallelising-Python-with-Threading-and-Multiprocessing

	https://www.quantstart.com/articles/Parallelising-Python-with-Threading-and-Multiprocessing

	== Tkinter and simple GUI programming ==		== Tkinter and simple GUI programming ==

Stefan: /* Threading */

2018-06-18T09:24:34Z

Threading

← Older revision		Revision as of 09:24, 18 June 2018
Line 1:		Line 1:
	== Threading ==		== Threading ==

	http://www.tutorialspoint.com/python/python_multithreading.htm		http://www.tutorialspoint.com/python/python_multithreading.htm

			Note however that threading in python is limited due to the GIL. To achieve "true" threading, use the "multiprocess" library (which in fact spawns different processes and uses IPC mechanism for communication etc):

			https://www.quantstart.com/articles/Parallelising-Python-with-Threading-and-Multiprocessing

	== Tkinter and simple GUI programming ==		== Tkinter and simple GUI programming ==

Stefan: /* One function proper hexdump */

2018-06-15T15:24:18Z

One function proper hexdump

← Older revision		Revision as of 15:24, 15 June 2018
Line 73:		Line 73:
	for k in range(left):		for k in range(left):
	s += " "		s += " "
	if left > 8:		if left >= 8:
	s += " "		s += " "
	s += " \|"		s += " \|"

Stefan: /* One function proper hexdump */

2018-06-15T15:14:38Z

One function proper hexdump

← Older revision		Revision as of 15:14, 15 June 2018
Line 37:		Line 37:
	The following function will convert a byte array to a format like this:		The following function will convert a byte array to a format like this:

	00000000 69 6d 70 6f 72 74 20 73 74 72 69 6e 67 0d 0a 0d \|import.string... \|		00000000 69 6d 70 6f 72 74 20 73 74 72 69 6e 67 0d 0a 0d \|import.string... \|
	00000010 0a 64 65 66 20 68 65 78 64 75 6d 70 28 63 76 65 \|.def.hexdump(cve \|		00000010 0a 64 65 66 20 68 65 78 64 75 6d 70 28 63 76 65 \|.def.hexdump(cve \|
	00000020 63 74 6f 72 2c 20 70 72 65 66 69 78 20 3d 20 22 \|ctor,.prefix.=." \|		00000020 63 74 6f 72 2c 20 70 72 65 66 69 78 20 3d 20 22 \|ctor,.prefix.=." \|
	00000030 22 29 3a 0d 0a 09 69 20 3d 20 30 0d 0a 09 73 20 \|"):...i.=.0...s. \|		00000030 22 29 3a 0d 0a 09 69 20 3d 20 30 0d 0a 09 73 20 \|"):...i.=.0...s. \|
	00000040 3d 20 22 22 0d 0a 09 61 63 20 3d 20 5b 5d 0d 0a \|=.""...ac.=.[].. \|		00000040 3d 20 22 22 0d 0a 09 61 63 20 3d 20 5b 5d 0d 0a \|=.""...ac.=.[].. \|
	00000050 09 66 6f 72 20 63 20 69 6e 20 63 76 65 63 74 6f \|.for.c.in.cvecto \|		00000050 09 66 6f 72 20 63 20 69 6e 20 63 76 65 63 74 6f \|.for.c.in.cvecto \|
	00000060 72 3a 0d 0a 09 09 69 66 20 6e 6f 74 20 69 20 25 \|r:....if.not.i.% \|		00000060 72 3a 0d 0a 09 09 69 66 20 6e 6f 74 20 69 20 25 \|r:....if.not.i.% \|
			00000070 20 31 36 3a 0d 0a 09 09 09 69 66 20 69 20 21 3d \|.16:.....if.i.!= \|

	The function is not designed to be memory efficient, fast or good looking, just simple to drop in and get some hex output.		The function is not designed to be memory efficient, fast or good looking, just simple to drop in and get some hex output.
Line 62:		Line 63:
	s += " \|"		s += " \|"
	ac = []		ac = []
	s += "\n%s%s " % (prefix, "%08x" % i)		s += "\n%s%s " % (prefix, "%08x " % i)
	elif not i % 8:		elif not i % 8:
	s += " "		s += " "

Stefan at 15:12, 15 June 2018

2018-06-15T15:12:47Z

← Older revision		Revision as of 15:12, 15 June 2018
Line 33:		Line 33:
	root.after(10, drawframe)		root.after(10, drawframe)
	mainloop()		mainloop()

			== One function proper hexdump ==
			The following function will convert a byte array to a format like this:

			00000000 69 6d 70 6f 72 74 20 73 74 72 69 6e 67 0d 0a 0d \|import.string... \|
			00000010 0a 64 65 66 20 68 65 78 64 75 6d 70 28 63 76 65 \|.def.hexdump(cve \|
			00000020 63 74 6f 72 2c 20 70 72 65 66 69 78 20 3d 20 22 \|ctor,.prefix.=." \|
			00000030 22 29 3a 0d 0a 09 69 20 3d 20 30 0d 0a 09 73 20 \|"):...i.=.0...s. \|
			00000040 3d 20 22 22 0d 0a 09 61 63 20 3d 20 5b 5d 0d 0a \|=.""...ac.=.[].. \|
			00000050 09 66 6f 72 20 63 20 69 6e 20 63 76 65 63 74 6f \|.for.c.in.cvecto \|
			00000060 72 3a 0d 0a 09 09 69 66 20 6e 6f 74 20 69 20 25 \|r:....if.not.i.% \|

			The function is not designed to be memory efficient, fast or good looking, just simple to drop in and get some hex output.

			import string

			def hexdump(cvector, prefix = ""):
			i = 0
			s = ""
			ac = []
			for c in cvector:
			if not i % 16:
			if i != 0:
			s += " \|"
			for cs in ac:
			css = chr(cs)
			s += css if css in string.printable and not css in string.whitespace else "."
			s += " \|"
			ac = []
			s += "\n%s%s " % (prefix, "%08x" % i)
			elif not i % 8:
			s += " "
			s += "%02x " % c
			ac.append(c)
			i += 1
			if len(ac) > 0:
			left = 16 - len(ac)
			for k in range(left):
			s += " "
			if left > 8:
			s += " "
			s += " \|"
			for cs in ac:
			css = chr(cs)
			s += css if css in string.printable and not css in string.whitespace else "."
			for k in range(left):
			s += " "
			s += " \|"

			return s

			with open("hexdump.py", "rb") as f:
			data = f.read()
			print(hexdump(data))

Stefan at 23:40, 23 May 2016

2016-05-23T23:40:39Z

← Older revision		Revision as of 23:40, 23 May 2016
Line 1:		Line 1:
			== Threading ==
			http://www.tutorialspoint.com/python/python_multithreading.htm

	== Tkinter and simple GUI programming ==		== Tkinter and simple GUI programming ==

Stefan: /* Tkinter */

2016-05-23T19:31:23Z

Tkinter

← Older revision		Revision as of 19:31, 23 May 2016
Line 1:		Line 1:
	== Tkinter ==		== Tkinter and simple GUI programming ==

	#!/usr/bin/env python		#!/usr/bin/env python

Stefan: Created page with "== Tkinter == #!/usr/bin/env python from Tkinter import * def drawframe(): c.delete("all") c.create_rectangle(0, 0, 150, 75 + c.steffe_i, fill="blue") c.steffe_i..."

2016-05-23T19:30:54Z

Created page with "== Tkinter == #!/usr/bin/env python from Tkinter import * def drawframe(): c.delete("all") c.create_rectangle(0, 0, 150, 75 + c.steffe_i, fill="blue") c.steffe_i..."

New page

== Tkinter ==

#!/usr/bin/env python

from Tkinter import *

def drawframe():
c.delete("all")
c.create_rectangle(0, 0, 150, 75 + c.steffe_i, fill="blue")
c.steffe_i += 1
root.after(10, drawframe)

def mouseclick(event):
print "Mouse click at", event.x, event.y

def keyclick(event):
print "Key click", event.keysym

root = Tk()
c = Canvas(root, width=640, height=480)
c.pack()

root.bind("<Key>", keyclick)
root.bind("<Button-1>", mouseclick)

c.config(borderwidth = 10)
c.config(background = "grey15")
c.steffe_i = 0

root.after(10, drawframe)
mainloop()