isin is a concept of checking if some value is contained in a list; That concept is used in Python with [pandas] and [numpy]
isin is a concept of checking if some value is contained in a list; That concept is used in Python with [pandas] and [numpy]
Questions tagged [isin]
147 questions
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how to use pandas isin function in 2d numpy array?
I have created a 2d numpy array with 2 rows and 5 columns.
import numpy as np
import pandas as pd
arr = np.zeros((2, 5))
arr[0] = [12, 94, 4, 4, 2]
arr[1] = [1, 3, 4, 12, 46]
I have also created a dataframe with two columns col1 and col2
list1 =…
Vesper
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1 answer
check which dates from column 'long_date' are also in array holy_date
i get an empty df although i know some rows should be in it
any thoughts how to fix this?
the df after the 7th line run looks like this:
long_date
country
2020-11-07
Portugal
2020-01-01
Portugal
the holy_date looks like this:…
student
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1
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1 answer
Conditions in python that are not hard-coded
I am trying to find a way to represent conditions for np.where() other than from within the code. In my example below,
import pandas as pd
import numpy as np
file='insert path'
df = pd.read_csv(file)
df.loc[:, ['col_a','col_b']] = df.loc[:,…
mikecbos
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1
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1 answer
Check if substring is in a string in a different DF, if it is then return value from another row
I want to check is a substring from DF1 is in DF2. If it is I want to return a value of a corresponding…
PythonBeginner
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2 answers
"ValueError: Columns must be same length as key" when filtering dataframe with isin(list)
I am trying to filter a column in my dataframe based on values from a list, here is the snippet of my code where it's going wrong (replaced values for simplicity's sake)
import pandas as pd
from pandas import…
cdlabs45
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1 answer
Why .isin() does not work but str.contains() does work for an object column in my pd.DataFrame()
The str.contains() method filters the dataframe to only contain values with "A":
df = pd.DataFrame({"City": ["A","B","C","D","A","A"]})
df[df["City"].str.contains("A")]
But if I try to use .isin() on the same dataframe the output results in an…
Joe
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0 answers
check if multiple conditions exist in row in a dataframe
I have a checklist (.csv) and lots of files (.csv). I want to read files if they are in the checklist.
Checklist dataframe has three columns: "Energy":
np.int32,"Potential": string ,"Try": np.int32
Files have meaningful
names:…
Amir Ghorbani
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1 answer
why is pandas's isin method returning False for matching None?
Suppose i have two equivalent dataframes:
df1 = pd.DataFrame({'a': [None, None, None]})
df2 = pd.DataFrame({'a': [None, None, None]})
When i use the isin method as such:
df1.isin(df2)
I get the following…
Yee Cheng
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2 answers
Pandas isin equivalent for float or int
I have a dataframe with column A populated with numbers 1-9. I want to filter just on numbers 2 and 3. isin does not work for float dtypes. Is there an alternative?
something similar to:
df=df.loc[df['ColA'].isin([2,3])]
fred.schwartz
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2 answers
Keeps rows that aren't in list
I have a dataframe with sales and offers.
df offer sales
0 £10 off appple 10
1 £10 off apple and samsung 20
I have a list of offers that I want to avoid, which for this example has only 1…
asd
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1 answer
Pandas groupby with isin for consecutive groups
I have a dataframe that looks like the following:
arr = pd.DataFrame([[0,0],[0,1],[0,4],[1,4],[1,5],[1,6],[2,5],[2,8],[2,6])
My desired output is booleans that represent whether the value in column 2 is in the next consecutive group or not. The…
lara_toff
- 413
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2 answers
Filter dataframe on second row using list
I have a dataframe that needs to be kept in the structure below.
df
One two three
date apple banana
2019-12-20 0 4
2020-01-03 10 5
Is there a way to keep only columns where the second row is contained…
asd
- 1,245
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1 answer
update column based on matching row values in other columns with condition
I need to replace the value in columns ending in _4 with an updated value based on what value they include in the other columns. if the first 3 columns contain 1, the fourth should be zero. if the first three columns contain zero, then the fourth…
b101
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How Do I Generate a List of Items Not Shared Between Two Dataframes
Basically, I have a single list of a bunch of unique items that are categorized by color (Items). I do some stuff and generate a dataframe with selected combinations of these unique items (Combinations). My goal is to make a list of the items from…
wein3967
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5 answers
Pandas count, sum, average specific range/ value for each row
i have big data, i want to count, sum, average for each row only between specific range.
df = pd.DataFrame({'id0':[10.3,20,30,50,108,110],'id1':[100.5,0,300,570,400,140], 'id2':[-2.6,-3,5,12,44,53], 'id3':[-100.1,4,6,22,12,42]})
id0 id1 …
Asghat Suicno
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