group-by Questions

2

I have a dataframe with a MultiIndex. 01.01 02.01 03.01 04.01 bar total1 40 52 18 11 total2 36 85 5 92 baz total1 23 39 45 70 total2 50 49 51 65 foo total1 23 97 17 97 total2 64 56 94 45 qux to...
Ratliff asked 21/8, 2016 at 19:2

14

Solved

I have a data frame with three string columns. I know that the only one value in the 3rd column is valid for every combination of the first two. To clean the data I have to group by data frame by f...
Minus asked 5/3, 2013 at 11:34

5

Solved

How can I using group by with union in T-SQL? I want to group by the first column of a result of union, I wrote the following SQL but it doesn't work. I just don't know how to reference the specifi...
Cunnilingus asked 22/10, 2009 at 3:8

17

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This is obviously simple, but as a numpy newbe I'm getting stuck. I have a CSV file that contains 3 columns, the State, the Office ID, and the Sales for that office. I want to calculate the percent...
Miramontes asked 29/4, 2014 at 23:30

7

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I have a table with 3 columns which looks like this: File User Rating (1-5) ------------------------------ 00001 1 3 00002 1 4 00003 2 2 00004 3 5 00005 4 3 00005 3 2 00006 2 3 Etc. I want to ge...
Lucania asked 1/6, 2011 at 20:28

6

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I want to split the following dataframe based on column ZZ df = N0_YLDF ZZ MAT 0 6.286333 2 11.669069 1 6.317000 6 11.669069 2 6.324889 6 11.516454 3 6.320667 5 11.516454 4 6.325556 5 11.516...
Corniculate asked 16/5, 2014 at 1:10

4

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I've written this code to find duplicates and it works fine: SELECT * FROM StyleTable GROUP BY Color HAVING count(*) > 1 The problem is, it's returning just one of the duplicate rows. Is it...
Landscapist asked 5/3, 2012 at 22:12

5

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This query seems to work perfectly on my older machine. However, on my new machine with MySQL 5.7.14 and PHP 5.6.25 it throws the error: Fatal error: Uncaught exception 'PDOException' with message...
Strasser asked 18/4, 2017 at 20:44

2

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It seems like there is no native function for that purpose in Presto SQL. Do you know any way to efficiently aggregate a group and return its median?
Arbutus asked 23/9, 2020 at 14:41

5

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I have a list of my objects: class MyObj { public String Title { get; set; } public Decimal Price { get; set; } public String OtherData { get; set; } } var list = new List<MyObj> { new ...
Audient asked 25/5, 2011 at 11:7

13

This should be straightforward, but the closest thing I've found is this post: pandas: Filling missing values within a group, and I still can't solve my problem.... Suppose I have the following dat...
Staple asked 13/11, 2013 at 22:43

2

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I have the following columns in Table A which records users fingerprint "transaction" every time they check in or check out from a building. CREATE TABLE user_transactions ( id serial PR...
Phenacite asked 20/12, 2011 at 16:10

7

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This is my dataframe: customer_name order_dates order_values 1 John 2010-11-01 15 2 Bob 2008-03-25 12 3 Alex 2009-11-15 5 4 John 2012-08-06 15 5 John 2015-05-07 20 Let's say I want to add an orde...
Wellhead asked 6/8, 2015 at 14:59

4

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I have an array of object that have different values like items=[{id:1,category:"cat_1" , title:"My title 1"},{id:2,category:"cat_2" , title:"My title 2"},{id:6,category:"cat_1" , title:"Another ...
Arsphenamine asked 24/3, 2018 at 7:0

11

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I have a table named forms with the following structure- GROUP | FORM | FILEPATH ==================================== SomeGroup | SomeForm1 | SomePath1 SomeGroup | SomeForm2 | SomePath2 ----------...
Burgle asked 31/5, 2012 at 9:16

11

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Suppose I want to calculate the proportion of different values within each group. For example, using the mtcars data, how do I calculate the relative frequency of number of gears by am (automatic/m...
Denbrook asked 4/7, 2014 at 14:31

9

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The docs show how to apply multiple functions on a groupby object at a time using a dict with the output column names as the keys: In [563]: grouped['D'].agg({'result1' : np.sum, .....: 'result2' ...
Tambourine asked 25/1, 2013 at 20:26

5

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I've been using PostgreSQL and now migrating to MySQL. In my queries, I'm using PostgreSQL's SELECT DISTINCT ON (col1, col2, col3), I was wondering if there is any counterpart of this statement i...
Relativity asked 16/7, 2013 at 9:56

4

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Given the below dataframe, if rows are grouped by first name and last name, how can I find and create new rows for a group that does not have a row for every type in the types list. So in the examp...
Wolfie asked 3/12, 2023 at 3:50

6

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I have the following data frame in IPython, where each row is a single stock: In [261]: bdata Out[261]: <class 'pandas.core.frame.DataFrame'> Int64Index: 21210 entries, 0 to 21209 Data colum...
Dateless asked 30/8, 2012 at 15:45

5

I want to write a criteria query using "group by" and want to return all the columns. Plane sql is like this: select * from Tab group by client_name order by creation_time; I understand that it...
Legitimist asked 21/12, 2012 at 21:52

4

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I'm trying to create a duplicate row if the row meets a condition. In the table below, I created a cumulative count based on a groupby, then another calculation for the MAX of the groupby. df['Pat...
Isobelisocheim asked 27/3, 2017 at 18:24

3

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What is the most efficient way to use groupby and in parallel apply a filter in pandas? Basically I am asking for the equivalent in SQL of select * ... group by col_name having condition I think t...
Woodard asked 28/2, 2014 at 20:45

6

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I am trying to create a new column 'ab_weighted' in a Pandas dataframe based on two columns 'a','b' in that dataframe grouped by 'c'. Specifically, I am trying to replicate the output from this R c...
Wadsworth asked 12/12, 2018 at 16:13

15

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How do I count the number of records returned by a group by query, For eg: select count(*) from temptable group by column_1, column_2, column_3, column_4 Gives me, 1 1 2 I need to count th...
Abelmosk asked 28/2, 2011 at 20:6

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