Advertisements I’m working with a pandas DataFrame and I noticed a difference in behavior when using the in operator. Here’s an example to illustrate this: import pandas as pd df = pd.DataFrame({‘a’: [4, 5, 6], ‘b’: [7, 8, 9]}) print(1 in df) print(type(df)) print(1 in df["a"]) print(type(df["a"])) Output: False <class ‘pandas.core.frame.DataFrame’> True <class ‘pandas.core.series.Series’> The… Read More Why the difference in checking for value of pd.DataFrame vs pd.Series if value in index?

Advertisements df <- data.frame(x=c("a","b","c"), y = c(100,200,300)) v <- 1:4 I’m trying to add the vector v to a dataframe df such that each row of df is combined with each element of v x y v a 100 1 a 100 2 a 100 3 a 100 4 b 200 1 b 200 2… Read More Use expand.grid on data.frame and vector

Advertisements This is my DataFrame: import pandas as pd df = pd.DataFrame( { ‘close’: [109, 109, 105, 110, 105, 120, 120, 11, 90, 100], ‘high’: [110, 110, 108, 108, 115, 122, 123, 1120, 1000, 300], ‘target’: [107, 107, 107, 107, 107, 124, 124, 500, 500, 500] } ) Masks are: m1 = ( (df.high >… Read More How can I get the first row that meets conditions of a mask if another condition is not present before it?

Advertisements I would like to keep columns that contains word "FAIL". Input data: Values1 Values2 Values3 Status1 Status2 Status3 1 1 1 PASS PASS FAIL 2 2 2 PASS PASS PASS 3 3 3 PASS PASS PASS 4 4 4 PASS FAIL PASS Expected output: Status2 Status3 PASS FAIL FAIL PASS Current Output: Status1 Status2… Read More Keep columns that contains text in pandas dataframe

Advertisements Suppose I have a list of list of numbers that happen to be encoded as strings. import pandas as pd pylist = [[‘1′, ’43’], [‘2′, ’42’], [‘3′, ’41’], [‘4′, ’40’], [‘5′, ’39’]] Now I want a dataframe where these numbers are integers. I can see from pandas documentation that I can force a data… Read More Confusing conversion of types in pandas DataFrame

Advertisements I try to get my head around a solution for a lookup and filling of an additional column in a pandas dataframe for readability. The following data (truncated) is available where manager_id is filled with the corresponding user_ids last_name first_name user_id manager_id scorsese martin 1 2 wenders wim 2 2 kurosawa akira 3 3… Read More Adding values to a dataframe based on lookup in the same dataframe

Advertisements I am trying to merge two dataframes in quite a specific way. They are each similar to these two: df1 <- data.frame(Countries = c("Portugal", "Andorra", "Spain", "Portugal", "Portugal", "Portugal", "Spain"), Year_of_order = c("2015", "2016", "2014", "2016", "2014", "2015", "2015"), Type_of_order = c("vegetables", "meat", "fruits", "fruits", "meat", "vegetable", "meat") ) df2 <- data.frame(Names = c("Andorra",… Read More How to add values of one dataframe to another, double-conditioned by the receiving dataframe?

Advertisements I have a Dataset downloaded from Kaggle for my project, I would like to seek help in creating new columns and assigning its values based on an existing column. My actual Dataset is complicated, I will give a similar but simpler dataset for easy discussion. Input: Month | Fruit | Weight ——- ——– ——–… Read More Dataframe: create new columns and assign its values from existing column's values

Advertisements I have two long dataframes like so: df1 = pd.DataFrame([[1, 1], [2, 1], [3, 1], [2, 1], [2, 2], [3, 2], [5, 3]], columns=[‘value’, ‘id’]) df2 = pd.DataFrame([1, 2, 3, 4]) The first column of df1 act as the value, while the second column is an ID column. What I want to do is… Read More Multiply two pandas dataframe by index

Advertisements I’m working in a ML script and I want to change the values of a column by the same, but instead of string, stored as an array. Now the data is stored like this: ’31-2′, and I want to store as ‘[31,2]’. However, I get ValueError: Must have equal len keys and value when… Read More don't understand ValueError: Must have equal len keys and value when setting with an iterable in Python