pandas concat ignore_index doesn’t work

If I understood you correctly, this is what you would like to do. import pandas as pd df1 = pd.DataFrame({‘A’: [‘A0’, ‘A1’, ‘A2’, ‘A3’], ‘B’: [‘B0’, ‘B1’, ‘B2’, ‘B3’], ‘D’: [‘D0’, ‘D1’, ‘D2’, ‘D3’]}, index=[0, 2, 3,4]) df2 = pd.DataFrame({‘A1’: [‘A4’, ‘A5’, ‘A6’, ‘A7’], ‘C’: [‘C4’, ‘C5’, ‘C6’, ‘C7’], ‘D2’: [‘D4’, ‘D5’, ‘D6’, ‘D7’]}, index=[ … Read more

MySQL select with CONCAT condition

The aliases you give are for the output of the query – they are not available within the query itself. You can either repeat the expression: SELECT neededfield, CONCAT(firstname, ‘ ‘, lastname) as firstlast FROM users WHERE CONCAT(firstname, ‘ ‘, lastname) = “Bob Michael Jones” or wrap the query SELECT * FROM ( SELECT neededfield, … Read more

ffmpeg concat: “Unsafe file name”

The answer stated by @Mulvya (thank you!) works: “Add -safe 0 before -i“. Then another problem appeared with find STREAM -name ‘*’ -printf “file ‘$PWD/%p’\n” which returns the empty path as first entry. I changed this for for f in ./*.wav; do echo “file ‘$PWD/$f'”; done (see https://trac.ffmpeg.org/wiki/Concatenate) and now it seems to work. Hurray!

Merge two dataframes by index

Use merge, which is an inner join by default: pd.merge(df1, df2, left_index=True, right_index=True) Or join, which is a left join by default: df1.join(df2) Or concat), which is an outer join by default: pd.concat([df1, df2], axis=1) Samples: df1 = pd.DataFrame({‘a’:range(6), ‘b’:[5,3,6,9,2,4]}, index=list(‘abcdef’)) print (df1) a b a 0 5 b 1 3 c 2 6 d … Read more

Is there any haskell function to concatenate list with separator?

Yes, there is: Prelude> import Data.List Prelude Data.List> intercalate ” ” [“is”,”there”,”such”,”a”,”function”,”?”] “is there such a function ?” intersperse is a bit more general: Prelude> import Data.List Prelude Data.List> concat (intersperse ” ” [“is”,”there”,”such”,”a”,”function”,”?”]) “is there such a function ?” Also, for the specific case where you want to join with a space character, there … Read more