Pandas adding scalar value to numeric column?

2024/11/15 10:03:30

Given a dataframe like this

   ImageId | Width | Height | lb0 | x0 | y0 | lb1 | x1 | y1 | lb2 | x2 | y2
0  abc     | 200   | 500    | ijk | 115| 8  | zyx | 15 | 16 | www | 23 | 42
1  def     | 300   | 800    | ijk | 91 | 23 | zyx | 16 | 15 | www | 8  | 4
2  ghi     | 700   | 400    | ijk | 230| 16 | zyx | 17 | 24 | www | 43 | 109
3  jkl     | 500   | 100    | ijk | 46 | 23 |     |    |    |     |    |
...

When I try to add to a column with

df['x0'] = df['x0'] + 1

I now get column x0 as follows:

151
127
266
82

Question:

  • How do I add a scalar value to a whole column in Pandas?
Answer

You probably don't have an int dtype. Doing

df['x0'] = df['x0'].astype(int) + 1

should work

https://en.xdnf.cn/q/72456.html

Related Q&A

Sklearn Pipeline all the input array dimensions for the concatenation axis must match exactly

import pandas as pd from sklearn.feature_extraction.text import CountVectorizer, TfidfTransformer from sklearn.pipeline import Pipeline from sklearn.svm import LinearSVC from sklearn.preprocessing impo…

Python Pandas read_excel returns empty Dataframe

Reading a simple xls returning empty dataframe, cant figure it out for the life of me:path = (c:/Users/Desktop/Stuff/Ready) files = os.listdir(path) print(files)files_xlsx = [f for f in files if f[-3:]…

Fill matrix with transposed version

I have a pairwise matrix:>>> ma b c d a 1.0 NaN NaN NaN b 0.5 1.0 NaN NaN c 0.6 0.0 1.0 NaN d 0.5 0.4 0.3 1.0I want to replace the NaN in the the top right with the same va…

Subclass of numpy ndarray doesnt work as expected

`Hello, everyone.I found there is a strange behavior when subclassing a ndarray.import numpy as npclass fooarray(np.ndarray):def __new__(cls, input_array, *args, **kwargs):obj = np.asarray(input_array)…

How to correctly load images asynchronously in PyQt5?

Im trying to figure out how to accomplish an async image load correctly, in PyQt Qlistview.My main widget consists of a Qlistview and a QLineEdit textbox. I have a database of actors which I query usin…

How to print results of Python ThreadPoolExecutor.map immediately?

I am running a function for several sets of iterables, returning a list of all results as soon as all processes are finished.def fct(variable1, variable2):# do an operation that does not necessarily ta…

Python dir equivalent in perl?

The dir command in Python 2.7.x lists all accessible symbols from a module. Is there an equivalent in Perl 5.x to list all accessible symbols from a package?

Entire JSON into One SQLite Field with Python

I have what is likely an easy question. Im trying to pull a JSON from an online source, and store it in a SQLite table. In addition to storing the data in a rich table, corresponding to the many fiel…

Python scipy module import error due to missing ._ufuncs dll

I have some troubles with sub-module integrate from scipy in python. I have a 64 bits architecture, and it seems, according to the first lines of the python interpreter (see below) that I am also using…

How can I call python program from VBA?

Just as the title goes.I have a python program which processes some data file I downloaded from email.I am writing a vba script which can download the email attachments and execute the python program t…