All Questions
627 questions
2
votes
2
answers
62
views
Pandas: Fill in missing values with an empty numpy array
I have a Pandas Dataframe that I derive from a process like this:
df1 = pd.DataFrame({'c1':['A','B','C','D','E'],'c2':[1,2,3,4,5]})
df2 = pd.DataFrame({'c1':['A','B','C'],'c2':[1,2,3],'c3': [np.array((...
- 289
0
votes
3
answers
40
views
How to multiply the elements of an array to the corresponding elements of a set of DataFrames?
How do I multiply the elements of an array to the corresponding elements of a set of DataFrames? My matrices are quite large, but for the sake of simplicity I will use only a 2x3 dimension:
For ...
- 61
0
votes
2
answers
72
views
How to convert string scientific notation to float within a txt file
I have code in a .txt file that has scientific notation values stored as strings and I am trying to convert them to floats that way I can perform calculations on them. However, when I try to attempt ...
- 13
0
votes
2
answers
49
views
How to copy values between 2 dataframes based on similar/matching items in multiple columns? [duplicate]
I have 2 dataframes (df1 and df2) and they look like this:
df1
index gameID Team A B C
0 0001 Lakers 10 100 90
1 0001 Clippers 20 105 91
2 ...
- 1
0
votes
2
answers
47
views
Create Pivot table and add additional columns from another dataframe
Given two identically formatted dataframes:
df1
Counterparty Product Deal Date Value
foo bar Buy 01/01/24 10.00
foo bar Buy 01/01/24 10.00
foo ...
- 1,885
0
votes
2
answers
53
views
Extracting wrapped column data
I have a particular data file that has 7 columns total: 1 column of time and 6 columns of data. As depicted in the image I attached, the first column represents time, while the next four columns ...
- 151
0
votes
1
answer
55
views
Is there a way to compute this table in Python?
I'm having trouble computing this table in python since the x-axis and y-axis have ranges. Is there a way I can input this table without manually putting in all numbers within the ranges? For example, ...
- 1
0
votes
0
answers
111
views
ADTK Visualization: ValueError: Multi-dimensional indexing (e.g. `obj[:, None]`) is no longer supported
I have tried to reproduce the examples from anomaly detection tutorial: https://adtk.readthedocs.io/en/stable/notebooks/demo.html#ThresholdAD
When I use this to plot:
from adtk.visualization import ...
- 175
0
votes
4
answers
109
views
Efficient way to iterate rows in two arrays and then copy array back into a dataframe
I am learning numpy and I have a dataframe of asset prices and thought it might be better to do a calculation in numpy and then put the data back into a dataframe when done. I have a working program ...
- 91
1
vote
1
answer
59
views
How to split an array using its minimum entry
I am trying to split a dataset into two separate ones by finding its minimum point in the first column. I have used idxmin to firstly identify the location of the minimum entry and secondly iloc to ...
- 25
1
vote
1
answer
77
views
Adding numpy arrays to cells of a pandas DataFrame depends on initialisation
I was trying to add a list of numpy arrays as elements to the pandas DataFrame:
DataFrame
using:
df.loc[df['B']==4,'A'] = [np.array([5, 6, 7, 8]),np.array([2,3])]
Whether or not this is allowed seems ...
- 13
0
votes
2
answers
79
views
Sum cell values below until a blank cell with Python
I am looking for a Python code that enables me to sum all the values within a column (e.g. Column A) until a blank cell is reached. This process should then repeat itself until the end of the column.
...
0
votes
2
answers
106
views
How to find first value from an array column which matches a substring in a different column? PySpark
I'm trying to select the first instance of an element in an array column which matches a substring in a different column, and then create a different column with the selected element, like this:
col_a
...
- 11
0
votes
4
answers
97
views
Build Pandas DataFrame from a list array with new column as list names
I would like to convert a list of arrays of varying array shapes like this:
import numpy as np
import pandas as pd
data = [np.array([[1, 2, 3], [1, 3, 2], [1, 1, 2]]),
np.array([[1, 3, 3], [2,...
-3
votes
1
answer
139
views
Error when dividing DataFrame values by 255 in Python
I am encountering a TypeError when attempting to normalize the values in a pandas DataFrame by dividing them by 255 in Python. The error message is as follows:
TypeError: unsupported operand type(s) ...
- 58