What is the most efficient way to toggle between 0 and 1? Answer Solution using NOT If the values are boolean, the fastest approach is to use the not operator: Solution using subtraction If the values are numerical, then subtraction from the total is a simple and fast way to toggle values: Solution using XOR …
Tag: python
How can I fire a Traits static event notification on a List?
I am working through the traits presentation from PyCon 2010. At about 2:30:45 the presenter starts covering trait event notifications, which allow (among other things) the ability to automatically call a subroutine any time a trait has changed. I am running a modified copy of the example he gave… In th…
Will the function in python for loop be executed multiple times?
Say I have the following class with a method returning a list: If I loop over the list returned fro the method, as follows: Inside the for loop, will c.f() be executed multiple times? If yes, in order to get it once, do I have to do assignment outside of the loop, or there is some trivial way? Answer Seems
Convert ASCII chars to Unicode FULLWIDTH latin letters in Python?
Can you easily convert between ASCII characters and their Asian full-width Unicode wide characters? Like: to Answer Those “wide” characters are named FULLWIDTH LATIN LETTER: http://www.unicodemap.org/range/87/Halfwidth%20and%20Fullwidth%20Forms/ They have range 0xFF00 – -0xFFEF. You can make…
Finding all possible permutations of a given string in python
I have a string. I want to generate all permutations from that string, by changing the order of characters in it. For example, say: what I want is a list like this, Currently I am iterating on the list cast of the string, picking 2 letters randomly and transposing them to form a new string, and adding it to s…
Why am I getting ugly curly brackets around my text in the label widget? – Tkinter
I’m getting curly brackets around the text in my label widget. The output is {Total tries: 0} instead of Total tries: 0. Here is a short version of my code: Answer There is a comma at the end of the line. The comma changes the value being assigned to self.label[“text”] from a string to a tup…
PySerial [Error 5] Access is Denied
I am trying to write a program in Python that will loop to keep checking the serial port (COM4) and print out a message when the character “1” is read from the serial port. I want to send “1” over the serial port from an Arduino gadget upon the push of a button. However, I get the erro…
Proxies with Python ‘Requests’ module
Just a short, simple one about the excellent Requests module for Python. I can’t seem to find in the documentation what the variable ‘proxies’ should contain. When I send it a dict with a standard “IP:PORT” value it rejected it asking for 2 values. So, I guess (because this doesn…
JavaScript function similar to Python range()
Is there a function in JavaScript similar to Python’s range()? I think there should be a better way than to write the following lines every time: Answer No, there is none, but you can make one. JavaScript’s implementation of Python’s range() Trying to emulate how it works in Python, I would …
Remove all whitespace in a string
I want to eliminate all the whitespace from a string, on both ends, and in between words. I have this Python code: But that only eliminates the whitespace on both sides of the string. How do I remove all whitespace? Answer If you want to remove leading and ending spaces, use str.strip(): If you want to remove…