I’m trying to make a spider that gets some outdated urls from database, parses it and updates data in database. I need to get urls to scrape and ids to use it pipeline that saves the scraped data. I made this code, but I don’t know why scrapy changes the order of scraped links, looks like its rand…
Tag: python-3.x
Color formatting excel file row in python
I have dataframe where I have 2 Date columns. I have to compare them and if they are different then whole row should be colored. Please check the picture. Please guide me how can I do that in python. Thanks in advance. Answer Create styles in helper DataFrame and export to excel:
When are static variables initialized in Python?
Consider the following code When exactly does the initialization of i take place? Before the execution of the init method or after it? Answer Before. The __init__ method isn’t run until Foo is instantiated. i=1 is run whenever the class definition is encountered in the code You can see this by adding pr…
Formatting a float number without trailing zeros
When I do a simple division in Python 3, such as 123000/1000, I get 123.0, or 4/2 I get 2.0. How do I get rid of the trailing zero in Python 3’s division? EDIT: I don’t want just simple integer division. For ex, 1234/1000 should give 1.234. To be clear, this question is about formatting the output…
What does a star (asterisk) do in f-string?
In the python document 2.4.3. Formatted string literals, it seems possible to write a star followed by an expression in a f-string’s {}, but I cannot find how to use that. What’s that and how I can use it? Is it documented somewhere? To be exact, this is regarding “*” or_expr part of t…
Subset-AVG – Finding a subset of List Which Matches Known Rational Number
I’ve asked this on math overflow and used comments to clarify/overstate my question. I hope it has the intended effect and doesn’t come off as jarring. I’m attempting to find what subset of numbers reach a known average. I have a list of known values, negative and possible decimals. They loo…
How to access a smart contract function protected by access rights using Web3py?
I have a smart contract address for security tokens, and certain functions of it are protected by access rights, for which I have an address to access those functions, however I am not able to figure out, how to call that function by specifying the rights. Can someone tell me, how do I provide the access righ…
Why is `object` an instance of `type` and `type` an instance of `object`?
I am a little bit confused about the object and type classes in Python 3. Maybe someone can clear up my confusion or provide some additional information. My current understanding is that every class (except object) inherits from a base class called object. But every class (including object) is also an instanc…
Are there disadvantages of using __slots__?
I’m using Python 3.7 and Django. I was reading about __slots__ . Evidently, __slots__ can be used to optimize memory allocation for a large number of those objects by listing all the object properties ahead of time. My perhaps obvious question is why wouldn’t we want to do this for all objects? Ar…
Modify this program so that before it creates the window, it prompts the user to enter the desired background color
When I write a script and run it. Python Terminal starts doing it, but when it comes to prompting a color my program skips this step. The goal is: Modify this program so that before it creates the window, it prompts the user to enter the desired background color. It should store the user’s responses in a vari…