I have a dataframe with missing data in several columns. In some of these columns, say ‘Col_A’ to ‘Col_D’, I’d like to replace them with 0. I tried it this way: but I got the error message <lambda>() takes 1 positional argument but 2 were given. Eventually, I changed my sol…
Tag: lambda
Adding functions y(x) together in python – impossible?
I’m currently trying to solve an engineering problem where I need to solve relatively long differential equations, for which I’m using the method odeint from scipy. I changed my problem to more easy variables and equations to shorten the code below and make it clearer. I want to add two parts of a…
Factorial function using lambda
I am trying to implement the function below into one line of lambda code. I have constructed a lambda statement, but I keep getting syntax error: Answer First of all, you can’t refer to a global name z when there is a local variable (the parameter) by the same name. Thus, we will declare a lambda statem…
Pandas – iloc – comparing value to the cell below
For the following table: Using Pandas – I would like achieve the desired_output column, that is TRUE when the value below the current cell i different – otherwise FALSE. I have tried the following code – but error occurs. Answer
Using filter and lambda in a list of lists
I working with a list of lists. Each of those lists are the same — they contain title, url and some additional statistics (always in the same order). I would like to create a function find_title, which takes the wanted title and returns the whole list (with title, url and statistics). That’s my at…
Nested lambda statements when sorting lists
I wish to sort the below list first by the number, then by the text. Attempt 1 I was not happy with this since it required splitting a string twice, to extract the relevant components. Attempt 2 I came up with the below solution. But I am hoping there is a more succinct solution via Pythonic lambda statements…
How to use await in a python lambda
I’m trying to do something like this: But I get this error: Which makes sense because the lambda is not async. I tried to use async lambda x: … but that throws a SyntaxError: invalid syntax. Pep 492 states: Syntax for asynchronous lambda functions could be provided, but this construct is outside o…
How to sort by value efficiently in PySpark?
I want to sort my K,V tuples by V, i.e. by the value. I know that TakeOrdered is good for this if you know how many you need: Using TakeOrdered: Using Lambda I’ve checked out the question here, which suggests the latter. I find it hard to believe that takeOrdered is so succinct and yet it requires the s…
How to remove string value from column in pandas dataframe
I am trying to write some code that splits a string in a dataframe column at comma (so it becomes a list) and removes a certain string from that list if it is present. after removing the unwanted string I want to join the list elements again at comma. My dataframe looks like this: So basically my goal is to
python max function using ‘key’ and lambda expression
I come from OOP background and trying to learn python. I am using the max function which uses a lambda expression to return the instance of type Player having maximum totalScore among the list players. The function correctly returns instance of type Player having maximum totalScore. I am confused about the fo…