I am building a CSV chunk by chunk using the csv module from the standard library. This means that I am adding rows one by one in a loop. Each row that I add contains information for each column of my dataframe. So, I have this CSV: And I am adding rows one by one: And so on. My problem
Tag: python-3.x
Can One Replace or Remove a specific key from functools.lru_cache?
I’m using a functools.lru_cache to serve temp file paths given certain input*. However in case the path no longer exists, I would like to remove/replace the single corresponding key. The cache_clear() method would be overkill and cache_info() do not appear to help. Thanks for your help! * The method being cached streams a fileobj from S3 to a local temp
Instance error in OOP design: Instance of Card has No points member
I’m reading this book called Master Object Oriented programming Python by Steven Lott. I came across this code: I’m not able to understand how can self._points() in Card be legal expression. I run the code in compiler too it stats the following error Instance of Card has No points member Full Code I have kept it as gist here Answer
pip3: bad interpreter: No such file or directory
I am trying to install dependencies using pip3 command current scenario: I have no idea why my pip3 command is not working. I have tried things like this: Answer You’ve got a whole slew of different Python installations, plus at least one former Python installation that you deleted. Situations like this are exactly why running pip or pip3 directly is
Difference between Standard scaler and MinMaxScaler
What is the difference between MinMaxScaler() and StandardScaler(). mms = MinMaxScaler(feature_range = (0, 1)) (Used in a machine learning model) sc = StandardScaler() (In another machine learning model they used standard-scaler and not min-max-scaler) Answer From ScikitLearn site: StandardScaler removes the mean and scales the data to unit variance. However, the outliers have an influence when computing the empirical mean
What is the use of bincount() method from numpy?
What is its purpose? I tried reading the official site but wasn’t able to understand. Answer bincount returns the count of values in each bin from 0 to the largest value in the array i.e. e.g. Note: absent numbers (e.g. 5 above) return a count of 0 a ValueError is raised if the list contains negative numbers or NaN
loading EMNIST-letters dataset
I have been trying to find a way to load the EMNIST-letters dataset but without much success. I have found interesting stuff in the structure and can’t wrap my head around what is happening. Here is what I mean: I downloaded the .mat format in here I can load the data using it is a dictionnary with the keys as
TypeError: fit_transform() missing 1 required positional argument: ‘X’
I am trying to do Feature Scaling in a dataset, but I get an error and have no idea how to proceed: and here is my code: Answer You are assigning sc_X a reference to the StandardScaler class. but fit_transform() is is not a class method, but an instance method. This means that you have to create an instance of
Find out the percentage of missing values in each column in the given dataset
input is https://query.data.world/s/Hfu_PsEuD1Z_yJHmGaxWTxvkz7W_b0 and the output should be Answer How about this? I think I actually found something similar on here once before, but I’m not seeing it now… And if you want the missing percentages sorted, follow the above with: As mentioned in the comments, you may also be able to get by with just the first line in
Delete rows with date’s before the required date point based on key value
I have a pd.dataframe that looks like this: So now based on the key_value, I want to drop all the rows that have their date column value before 2018-04-01 I want to have an end output like this: Answer You can just filter your dataframe using Boolean indexing. There is no groupwise operation here. Just remember to convert your series