Combining data based on column in spark - apache-spark

I have data in following format in hive table.
user | purchase | time_of_purchase
I want to get data in
user | list of purchases ordered by time
How do I do this in pyspark or hiveQL?
I have tried using collect_list in hive but it does not retain the order correctly by timestamp.
Edit :
Adding sample data as asked by KartikKannapur.
Here is a sample data
94438fef-c503-4326-9562-230e78796f16 | Bread | Jul 7 20:48
94438fef-c503-4326-9562-230e78796f16 | Shaving Cream | July 10 14:20
a0dcbb3b-d1dd-43aa-91d7-e92f48cee0ad | Milk | July 7 3:48
a0dcbb3b-d1dd-43aa-91d7-e92f48cee0ad | Bread | July 7 3:49
a0dcbb3b-d1dd-43aa-91d7-e92f48cee0ad | Lotion | July 7 15:30
The output I want is
94438fef-c503-4326-9562-230e78796f16 | Bread , Shaving Cream
a0dcbb3b-d1dd-43aa-91d7-e92f48cee0ad | Milk , Bread , Lotion

One way of doing this is
First create a hive context and read table to a RDD.
from pyspark import HiveContext
purchaseList = HiveContext(sc).sql('from purchaseList select *')
Then process the RDD
from datetime import datetime as dt
purchaseList = purchaseList.map(lambda x:(x[0],[x[1],dt.strptime(x[2],"%b %d %H:%M")]))
purchaseByUser = purchaseList.groupByKey()
purchaseByUser = purchaseByUser.map(lambda x:(x[0],[y[0] for y in sorted(x[1], key=lambda z:z[1])]))
print(purchaseByUser.take(2))
Output
[('94438fef-c503-4326-9562-230e78796f16', ['Bread', 'Shaving Cream']), ('a0dcbb3b-d1dd-43aa-91d7-e92f48cee0ad', ['Milk', 'Bread', 'Lotion'])]
Save the RDD as new hive table
schema_rdd = HiveContext(sc).inferSchema(purchaseByUser)
schema_rdd.saveAsTable('purchaseByUser')
For reading and writing hive table see this stackoverflow question and spark docs

Related

Pandas: Sliding window, summing app 14 day data

I do wonder how it is possible to make sliding windows in Pandas.
I have a dataframe with three columns.
Country | Number | DayOfTheYear
===================================
No | 50 | 0
No | 20 | 1
No | 37 | 2
I would love to see 14 day chunks for every country and day combination.
The country think can be ignored for the moment, since I can filter those manually in some way. But imagine there is only one country, is there a smart way to get some sort of summed up sliding window, resulting in something like the following?
Country | Sum | DatesOftheYear
===================================
No | 504 | 0-13
No | 207 | 1-14
No | 337 | 2-15
I would also accept if if they where disjunct, being only 0-13, 14-27, etc.
But I just cannot come along with Pandas. I know an old SQL solution, but is there anybody having a nice idea for Pandas?
If you want a rolling windows of your dataframe, you can simply use the .rolling function of pandas : https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.rolling.html
In your case : df["Number"].rolling(14).sum()

Using multiple parent IDs for cutoff times in deep feature synthesis

My data looks like: People <-- Events <--Activities. The parent is People, of which the only variable is the person_id. Events and Activities both have a time index, along with event_id and activity_id, both which have a few features.
Members of the 'People' entity visit places at all different times. I am trying to generate deep features for people. If people is something like [1,2,3], how do I pass cut off times that create deep features for something like (Person,cutofftime): [1,January2], [1, January3]
If I have only 3 People, it seems like I can't pass a cutoff_time dataframe that has 10 rows (for example, person 1 with 10 possible cutoff times). Trying this gives me the error "Duplicated rows in cutoff time dataframe", despite dropping duplicates from my cutoff_times dataframe.
Must I include time index in the People Entity? This would leave my parent entity with multiple people in the index, although they would have different time index. My instinct is that the people entity should not include any datetime column. I would like to give cut off times to the DFS function.
My cutoff_times df.head looks like this, and has multiple instances of some people_id:
+-------------------------------------------+
| person_id time label |
+-------------------------------------------+
| 0 f_GZSVLYU 2019-12-06 0.0 |
| 1 f_ATBJEQS 2019-12-06 1.0 |
| 2 f_GLFYVAY 2019-12-06 0.5 |
| 3 f_DIHPTPA 2019-12-06 0.5 |
| 4 f_GZSVLYU 2019-12-02 1.0 |
+-------------------------------------------+
The Parent People Entity is like this:
+-------------------+
| person_id |
+-------------------+
| 0 f_GZSVLYU |
| 1 f_ATBJEQS |
| 2 f_GLFYVAY |
| 3 f_DIHPTPA |
| 4 f_DVOYHRQ |
+-------------------+
How can I make featuretools understand what I'm trying to do?
'Duplicated rows in cutoff time dataframe.' I have explored my cutoff_times df and there are no duplicate rows. Person_id, times, and labels all have multiple occurrences each but no 2 rows are the same. Could these duplicates the error is referring to be somewhere else in the EntitySet?
The answer is one row of the cutoff_df had the same ID and time but with different labels. That's a problem.

How to cycle a Pandas dataframe grouping by hierarchical multiindex from top to bottom and store results

I'm trying to create a forecasting process using hierarchical time series. My problem is that I can't find a way to create a for loop that hierarchically extracts daily time series from a pandas dataframe grouping the sum of quantities by date. The resulting daily time series should be passed to a function inside the loop, and the results stored in some other object.
Dataset
The initial dataset is a table that represents the daily sales data of 3 hierarchical levels: city, shop, product. The initial table has this structure:
+============+============+============+============+==========+
| Id_Level_1 | Id_Level_2 | Id_Level_3 | Date | Quantity |
+============+============+============+============+==========+
| Rome | Shop1 | Prod1 | 01/01/2015 | 50 |
+------------+------------+------------+------------+----------+
| Rome | Shop1 | Prod1 | 02/01/2015 | 25 |
+------------+------------+------------+------------+----------+
| Rome | Shop1 | Prod1 | 03/01/2015 | 73 |
+------------+------------+------------+------------+----------+
| Rome | Shop1 | Prod1 | 04/01/2015 | 62 |
+------------+------------+------------+------------+----------+
| ... | ... | ... | ... | ... |
+------------+------------+------------+------------+----------+
| Milan | Shop3 | Prod9 | 31/12/2018 | 185 |
+------------+------------+------------+------------+----------+
| Milan | Shop3 | Prod9 | 31/12/2018 | 147 |
+------------+------------+------------+------------+----------+
| Milan | Shop3 | Prod9 | 31/12/2018 | 206 |
+------------+------------+------------+------------+----------+
Each City (Id_Level_1) has many Shops (Id_Level_2), and each one has some Products (Id_Level_3). Each shop has a different mix of products (maybe shop1 and shop3 have product7, which is not available in other shops). All data are daily and the measure of interest is the quantity.
Hierarchical Index (MultiIndex)
I need to create a tree structure (hierarchical structure) to extract a time series for each "node" of the structure. I call a "node" a cobination of the hierarchical keys, i.e. "Rome" and "Milan" are nodes of Level 1, while "Rome|Shop1" and "Milan|Shop9" are nodes of level 2. In particulare, I need this on level 3, because each product (Id_Level_3) has different sales in each shop of each city. Here is the strict hierarchy.
Nodes of level 3 are "Rome, Shop1, Prod1", "Rome, Shop1, Prod2", "Rome, Shop2, Prod1", and so on. The key of the nodes is logically the concatenation of the ids.
For each node, the time series is composed by two columns: Date and Quantity.
# MultiIndex dataframe
Liv_Labels = ['Id_Level_1', 'Id_Level_2', 'Id_Level_3', 'Date']
df.set_index(Liv_Labels, drop=False, inplace=True)
The I need to extract the aggregated time series in order but keeping the hierarchical nodes.
Level 0:
Level_0 = df.groupby(level=['Data'])['Qta'].sum()
Level 1:
# Node Level 1 "Rome"
Level_1['Rome'] = df.loc[idx[['Rome'],:,:]].groupby(level=['Data']).sum()
# Node Level 1 "Milan"
Level_1['Milan'] = df.loc[idx[['Milan'],:,:]].groupby(level=['Data']).sum()
Level 2:
# Node Level 2 "Rome, Shop1"
Level_2['Rome',] = df.loc[idx[['Rome'],['Shop1'],:]].groupby(level=['Data']).sum()
... repeat for each level 2 node ...
# Node Level 2 "Milan, Shop9"
Level_2['Milan'] = df.loc[idx[['Milan'],['Shop9'],:]].groupby(level=['Data']).sum()
Attempts
I already tried creating dictionaries and multiindex, but my problem is that I can't get a proper "node" use inside the loop. I can't even extract the unique level nodes keys, so I can't collect a specific node time series.
# Get level labels
Level_Labels = ['Id_Liv'+str(n) for n in range(1, Liv_Num+1)]+['Data']
# Initialize dictionary
TimeSeries = {}
# Get Level 0 time series
TimeSeries["Level_0"] = df.groupby(level=['Data'])['Qta'].sum()
# Get othe levels time series from 1 to Level_Num
for i in range(1, Liv_Num+1):
TimeSeries["Level_"+str(i)] = df.groupby(level=Level_Labels[0:i]+['Data'])['Qta'].sum()
Desired result
I would like a loop the cycles my dataset with these actions:
Creates a structure of all the unique node keys
Extracts the node time series grouped by Date and Quantity
Store the time series in a structure for later use
Thanks in advance for any suggestion! Best regards.
FR
I'm currently working on a switch dataset that I polled from an sql database where each port on the respective switch has a data frame which has a time series. So to access this time series information for each specific port I represented the switches by their IP addresses and the various number of ports on the switch, and to make sure I don't re-query what I already queried before I used the .unique() method to get unique queries of each.
I set my index to be the IP and Port indices and accessed the port information like so:
def yield_df(df):
for ip in df.index.get_level_values('ip').unique():
for port in df.loc[ip].index.get_level_values('port').unique():
yield df.loc[ip].loc[port]
Then I cycled the port data frames with a for loop like so:
for port_df in yield_df(adb_df):
I'm sure there are faster ways to carry out these procedures in pandas but I hope this helps you start solving your problem

Distribution of time periods over rows with certain status (column value)

I have a Pyspark dataframe containing logs, with each row corresponding to the state of the system at the time it is logged, and a group number. I would like to find the lengths of the time periods for which each group is in an unhealthy state.
For example, if this were my table:
TIMESTAMP | STATUS_CODE | GROUP_NUMBER
--------------------------------------
02:03:11 | healthy | 000001
02:03:04 | healthy | 000001
02:03:03 | unhealthy | 000001
02:03:00 | unhealthy | 000001
02:02:58 | healthy | 000008
02:02:57 | healthy | 000008
02:02:55 | unhealthy | 000001
02:02:54 | healthy | 000001
02:02:50 | healthy | 000007
02:02:48 | healthy | 000004
I would want to return Group 000001 having an unhealthy time period of 9 seconds (from 02:02:55 to 02:03:04).
Other groups could also have unhealthy time periods, and I would want to return those as well.
Due to the possibility of consecutive rows with the same status, and since rows of different groups are interspersed, I am struggling to find a way to do this efficiently.
I cannot convert the Pyspark dataframe to a Pandas dataframe, as it is much too large.
How can I efficiently determine the lengths of these time periods?
Thanks so much!
the pyspark with spark-sql solution would look like this.
First we create the sample data-set. In addition to the dataset we generate row_number field partition on group and order by the timestamp. then we register the generated dataframe as a table say table1
from pyspark.sql.window import Window
from pyspark.sql.functions import row_number
from pyspark.sql.functions import unix_timestamp
df = spark.createDataFrame([
('2017-01-01 02:03:11','healthy','000001'),
('2017-01-01 02:03:04','healthy','000001'),
('2017-01-01 02:03:03','unhealthy','000001'),
('2017-01-01 02:03:00','unhealthy','000001'),
('2017-01-01 02:02:58','healthy','000008'),
('2017-01-01 02:02:57','healthy','000008'),
('2017-01-01 02:02:55','unhealthy','000001'),
('2017-01-01 02:02:54','healthy','000001'),
('2017-01-01 02:02:50','healthy','000007'),
('2017-01-01 02:02:48','healthy','000004')
],['timestamp','state','group_id'])
df = df.withColumn('rownum', row_number().over(Window.partitionBy(df.group_id).orderBy(unix_timestamp(df.timestamp))))
df.registerTempTable("table1")
once the dataframe is registered as a table (table1). the required data can be computed as below using spark-sql
>>> spark.sql("""
... SELECT t1.group_id,sum((t2.timestamp_value - t1.timestamp_value)) as duration
... FROM
... (SELECT unix_timestamp(timestamp) as timestamp_value,group_id,rownum FROM table1 WHERE state = 'unhealthy') t1
... LEFT JOIN
... (SELECT unix_timestamp(timestamp) as timestamp_value,group_id,rownum FROM table1) t2
... ON t1.group_id = t2.group_id
... AND t1.rownum = t2.rownum - 1
... group by t1.group_id
... """).show()
+--------+--------+
|group_id|duration|
+--------+--------+
| 000001| 9|
+--------+--------+
the sample dateset had unhealthy data for group_id 00001 only. but this solution works for cases other group_ids with unhealthy state.
One straightforward way (may be not optimal) is:
Map to [K,V] with GROUP_NUMBER as the Key K
Use repartitionAndSortWithinPartitions, so you will have all data for every single group in the same partition and have them sorted by TIMESTAMP. Detailed explanation how it works is in this answer: Pyspark: Using repartitionAndSortWithinPartitions with multiple sort Critiria
And finally use mapPartitions to get an iterator over sorted data in single partition, so you could easily find the answer you needed. (explanation for mapPartitions: How does the pyspark mapPartitions function work?)

Data Organization, by Country and Year

I currently have a spreadsheet of data that I am cleaning to import into a database for further analysis. Currently the format is this:
Country | Year | GDP
--------------------
USA | 1950 | 5
USA | 1951 | 6
...
GBR | 1950 | 4
GBR | 1951 | 5
And so on for many countries. What I want to do is transpose this data so that it is a table of Country by Year and each cell is a coordinate GDP(Country, Year). i.e.:
Country | 1950 | 1951 | ...
-------------------------
USA | 5 | 6 ...
GBR | 4 | 5
Is there an easy way to do such a transposition? I realize it does not work because each country is iterated over 'n' years so a classic transposition is unavailable, but the nice thing is the table is uniform in that each country has rows from 1950-2011. My workflow includes Excel, R and SQLite. Is there a way to structure an sql script to import the rows in this manner? I usually use a csv-to-sql converter tool but I want the db table structured in the manner of the second table.
The underlying reason for this task is that I am gathering health data from WHO (formatted like the second table) and economic indicators from Penn (formatted as in the first table), and going to look at correlations between the two, thus I want all tables to have the same schema, as to ensure the relational aspect of the database is intuitive. I tell you this because I figure someone might have an idea/workaround that might make my original request unnecessary/extraneous.

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