dataframe

about pandas dataframe reverse column’s data order

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Code import pandas as pd import numpy as np df = pd.DataFrame({"K1":[1,2,3],"K2":[4,5,6]}) df["result"] = (df["K1"].shift(1)*df["K2"]).fillna(1)[::-1] #line A print(df["result"]) print((df["K1"].shift(1)*df["K2"]).fillna(1)[::-1]) #line B print((df["K1"].shift(1)*df["K2"]).fillna(1)) # line C Output 0 1.0 1 5.0 2 12.0 Name: result, dtype: float64 2 12.0 1 5.0 0 1.0 dtype: float64 0 1.0 1 5.0 2 12.0 dtype: float64 Why column result … Read more

Pandas Randomly Data Choosing

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I’m a beginner in Pandas. I have a data file containing 10000 different information of users. This data contain 5 columns and 10000 rows. One of these columns is the district of the users and it divides users according to their living place(It defines just 7 different locations and in each of locations some number of users live). as an example, out of this 10000 users, 300 users live in USA and 250 Live in Canada and..
I want to define a DataFrame which includes five random rows of users with the distinct of: USA,Canada,LA,NY and Japan. Also, the dimensions needs to be 20*5. Can you please help me how to do that?
I know for choosing random I need to use

Dataframe column: to find (cumulative) local maxima

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In the below dataframe the column “CumRetperTrade” is a column which consists of a few vertical vectors (=sequences of numbers) separated by zeros. (= these vectors correspond to non-zero elements of column “Portfolio”). I would like to find the cumulative local maxima of every non-zero vector contained in column “CumRetperTrade”.
To be precise, I would like to transform (using vectorization – or other – methods) column “CumRetperTrade” to the column “PeakCumRet” (desired result) which gives for every vector ( = subset corresponding to ’Portfolio =1 ’) contained in column “CumRetperTrade” the cumulative maximum value of (all its previous) values. The numeric example is below. Thanks in advance!
PS In other words, I guess that we need to use cummax() but to apply it only to the consequent (where ‘Portfolio’ = 1) subsets of ‘CumRetperTrade’

How would I extract any word after second hyphen in pandas

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Below is my DF df = pd.DataFrame({'A': ['a', 'b', 'c', '0'], 'B': ['0xF188-abc-cde', '0xF188-abc-abcde', '0xF188-abc-1234', '0xF188-abc-tu231er']}) Now I want to add NEW column “EXTRACT” which is an extraction of column ‘B’ after second hyphen. Below is the Expected Column. df= pd.DataFrame({'A': ['a', 'b', 'c', '0'], 'B': ["0xF188-abc-cde", '0xF188-abc-abcde', '0xF188-abc-1234', '0xF188-abc-tu231er'], 'Extract':['cde', 'abcde', '1234', 'tu231er']}) Answers: … Read more

Pandas Dataframe Generating Two new columns in a Dataframe that generate a count based on Conditional Parameters

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Thank you for your time. I am not an advanced programmer. I am taking 1 programming course. I understand the basics and an okay amount of Python. Please don’t destroy the little confidence I have in programming. I realize the answer may exist but I haven’t found it yet with my searching skills.