Nettet11. jul. 2024 · You must pass a list of column names to select columns. Otherwise, it will be interpreted as MultiIndex; df ['A','D'] would work if df.columns was MultiIndex. The most obvious way is df.loc [:, ['A', 'B']] but there are other ways (note how all of them take lists): Nettet7. aug. 2024 · My question is quite simple: Is there any way to randomly choose columns from a dataframe in Pandas? To be clear, I want to randomly pick out n columns with …
python - select columns based on columns names containing a …
Nettet29. des. 2024 · If you want to select int64 columns and then update "in place", you can use: int64_cols = [col for col in df.columns if is_int64_dtype (df [col].dtype)] df … Nettet8. aug. 2024 · To be clear, I want to randomly pick out n columns with the values attached. I know there is such a method for randomly picking rows: import pandas as pd df = pd.read_csv (filename, sep=',', nrows=None) a = df.sample (n = 2) So the question is, does it exist an equivalent method for finding random columns? python pandas Share … the northwind apartments
python - Randomly selecting columns from dataframe - Stack …
NettetIn trying to select the first (when counting from zero) column in a 2D 4x4 array, I wrote the following script: import numpy a4x4=[list(range(4*i,4*(i+1))) for i in list(range(4))] … Nettet9. okt. 2015 · If you want to sort the columns by the name of the columns use pandas and .loc () if you prefer by column numner use .iloc () import pandas as pd df=pd.DataFrame ( [ [1, 2,5,2], [5,4, 5,4], [7,7, 8,1], [7,6,9,2]], columns= ['col_1', 'col_2', 'col_3', 'col_4']) df col_1 col_2 col_3 col_4 0 1 2 5 2 1 5 4 5 4 2 7 7 8 1 3 7 6 9 2 apply … Nettet17. feb. 2024 · #set index with first column df = df.set_index (0) #create MultiIndex cols = np.arange (len (df.columns)) df.columns = [ cols // 4, cols % 4] print (df) 0 1 0 1 2 3 0 1 2 3 0 A 1 2 3 4 51 52 53 54 B 11 22 23 24 71 72 73 74 #stack, reset index names, remove level and reset index df1 = df.stack ().rename_axis ( (None, None)).reset_index … the north wind and the sun barney