Questions tagged [pyspark]
The Spark Python API (PySpark) exposes the apache-spark programming model to Python.
112
questions
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12 views
Network flow dataset labeling
I have a network flow dataset with 500 mio. records that looks similar to this (highly simplified)
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0answers
15 views
PySpark Crossvalidation error
I want to do a very simple cross validation using LogisticRegression.
Here is my code:
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1
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0answers
55 views
Flattening of a structure field in pyspark is slow?
I am rather new to (py)spark. I am using a python UDF to compute several outputs. My idea was
to pack all the values in a StructType and then flatten the structure before collecting the result.
The ...
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0answers
24 views
Spark: How to run PCA parallelized? Only one thread used
I use pySpark and set my configuration like following:
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0answers
40 views
How to calculate latent vector for a user in ALS based on some new input?
So I have an ALS trained in pyspark but then I get some interactions from a new user that wasn't in the training set. I want to give recommendations to that new user without retraining the ALS based ...
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0answers
64 views
multi-label prediction with pySpark
I am new to Spark
I am using pyspark to predict a multi label results.
I have converted multi labels to binary
So my labels will look like this
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0answers
45 views
PicklingError in pyspark (PicklingError: Can't pickle <class '__main__.Person'>: attribute lookup Person on __main__ failed)
I am unable to pickle the below class. I am using data bricks 6.5 ML (includes Apache Spark 2.4.5, Scala 2.11)
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0answers
14 views
How to define schema so that I can store sklearn object in pyspark dataframe
Using @pandas_udf(schema, PandasUDFType.GROUPED_MAP), is there any workaround to return sklearn fitted models in data frame ?
Something like this -
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1answer
19 views
Creating more than one worker nodes for local windows machine [closed]
I am using windows laptop. And I installed apache spark for my laptop. And I try to measure spark performance by changing spark components. because of that I want to create more than one worker nodes ...
1
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1answer
143 views
Remove all columns where the entire column is null
I have a very dirty csv where there are several columns with only null values.
I would like to remove them. I am trying to select all columns where the count of null values in the column is not equal ...
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1answer
26 views
How to run Spark python code in Jupyter Notebook via command prompt
I am trying to import a data frame into spark using Python's pyspark module. For this, I used Jupyter Notebook and executed the code shown in the screenshot below
After that I want to run this in CMD ...
1
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0answers
440 views
cannot access hive from spark [closed]
I am trying to install a hadoop + spark + hive cluster.
I am using hadoop 3.1.2, spark 2.4.5 (scala 2.11 prebuilt with user-provided hadoop) and hive 2.3.3 (also tried 3.1.2 with the exact same ...
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1answer
51 views
Spark/Databricks: GPU does not appear to be utilized for ML regression (cross-validation, prediction) notebook
I have created and attached a notebook to a GPU-enabled Databricks cluster (6.4 ML (includes Apache Spark 2.4.5, GPU, Scala 2.11), EC2 type: p2.xlarge).
I have started running the notebook that ...
0
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1answer
53 views
Pyspark Dataframes to Pandas and ML Ops - Parallel Execution Hold?
If I convert a spark dataframe into a pandas dataframe and subsequently apply pandas operations and sklearn models to the dataset in databricks, will the operations from pandas and sklearn be ...
1
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3answers
489 views
Is there a cost associated with converting Koalas dataframe to Spark dataframe?
I know that pandas works "under the hood" with numpy arrays stored in dictionaries. In contrast, Koalas works with the underlying Spark framework. Does that mean that there is no extra cost associated ...
1
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2answers
229 views
PySpark: How do I specify dropna axis in PySpark transformation?
I would like to drop columns that contain all null values using dropna(). With Pandas you can do this with setting the keyword argument ...
0
votes
1answer
119 views
How to apply K-Medoids in PySpark?
the pyspark ml library does not provide any clustering methods for K-Medoids. So my question is, how can one apply K-Medoids in a pyspark context?
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0answers
16 views
Tool/Technology/Framework to process file with 1GB
I'm new to datascience, but I have the following problem:
1) Read a file of 1GB, which each line is a json object
2) There are two more files, much smaller, which I need to JOIN some data
In this ...
0
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1answer
56 views
How to split a CSV into a dataframe without newline
Currently I'm using pyspark to make my df from a csv. However when I take the data in, it puts each element on a new line. Is there any way to keep the elements separate, and keep them on the same ...
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0answers
147 views
Machine learning after Cosine Similarity for fuzzy name matching
I am following ING Bank's Large Scale Fuzzy Name Matching and I have implemented their awesome_cossim_topn to produce a dataframe of names and their associated similarities. I then added the other ...
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0answers
145 views
Feature importance using logistic regression in pyspark
I am using logistic regression in PySpark. I have after splitting train and test dataset
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0answers
20 views
Online learning/ Incremental modelling in pyspark
Can online learning of a model is possible in Pyspark? Does Mlib library in pyspark supports that. If so how it can be done
0
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1answer
44 views
Incremental modelling of kmeans in pyspark
I have a large dataset and trained the model with kmeans for the first time. I saved the model and pipeline used . Now again I started collecting data. After sufficient data is collected using old ...
2
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1answer
162 views
Calculating Rank Ordering Error Metric for implicit recommendation
I'm reading Collaborative Filtering for Implicit Feedback Datasets. On page 6 they detail their evaluation strategy, which they define as mean Expected Percentile Ranking with the following formula:
$...
1
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1answer
3k views
How to select multiple columns in a RDD with Spark (pySpark)?
Lets say I have a RDD that has comma delimited data. Each comma delimited value represents the amount of hours slept in the day of a week.
So for i.e. [8,7,6,7,8,8,5]
How can I manipulate the RDD so ...
0
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0answers
9 views
(Py)Spark infrastructure for use in Java/C# website
Lets say I have experience creating ML models in Python, and have decided on training my models on Spark using Pyspark. This will form part of an ML infrastructure for a website with a Java or C# ...
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0answers
57 views
Running LSTM model on a big data sample using pyspark
I was wondering how does one run an LSTM model on a big dataframe in pyspark. Ideally, one wants to run the model parallelly on different nodes of a spark cluster. But how does one do that?
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95 views
Unseing label in PySpark MultilayerPerceptronClassifier
I'm trying to perform classification with a MLP in PySpark:
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0
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2answers
58 views
customer segmentation with unbalanced data
I am trying to do a customer segmentation on my transactional data and I am struggling a little bit on the best approach. Since it is an unsupervised model I can throw it to any algorithm and get some ...
1
vote
1answer
34 views
Which ML method for multiclass (non-binary) text classification should I choose (from SparkML)?
I am working on a quite big dataset that will be processed on the cluster, so this is why I am using PySpark for that purpose.
The presentable records of this dataset have a such structure:
...
0
votes
1answer
37 views
How to store subset of columns from a csv file?
I need to create a table in hive (or Impala) by reading from a csv file (named file.csv), ...
0
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0answers
61 views
Jupyter notebook pyspark error in %manage_spark
The environment is Jupyterhub on Centos using Pyspark kernel. When trying to run the below commands in JupyterLab I get errors. But the same commands work fine if I revert to regular Jupyter notebook ...
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0answers
50 views
Setting up Zeppelin to work with a Spark Cluster
I have made a spark cluster containing 2 workers and 1 master. I followed the following link to set up the spark clusters. After successfully setting up the spark clusters I wanted to connect it to ...
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1answer
100 views
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47 views
How to read binary video format in HDFS using pyspark?
We want to work on detection of pedestrians in a video using ML algorithm.But the video is in the HDFS file system.How can we read the binary video file format from HDFS using spark?
Please help me ...
0
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1answer
41 views
Regarding join in pyspark
Given a rdd in pyspark, $A=[(0, 1), (1, 2), (1, 3), (3, 0)]$
I am trying to find self join of A such that the second element of previous pair is equal to first element of next pair i.e.
$...
1
vote
1answer
2k views
PicklingError: Could not serialize object: TypeError: can't pickle fasttext_pybind.fasttext objects
I built a fasttext classification model in order to do sentiment analysis for facebook comments (using pyspark 2.4.1 on windows). When I use the prediction model function to predict the class of a ...
5
votes
1answer
247 views
Pyspark: Filter dataframe based on separate specific conditions
How can I select only certain entries that match my condition and from those entries, filter again using regex?
For instance, I have this dataframe (df)
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0answers
47 views
Where is $SPARK_HOME on an EC2 instance?
I am working on an EC2 instance with anaconda and pyspark pre-installed. My $SPARK_HOME variable is not set. Any ideas on how to locate my spark home?
1
vote
2answers
143 views
Record Linkage problem
I am building Matching Alogoritm using ML.Project is to match Internal customer data with external customer data.Features are names,address,city,state and zip.
We create pairs between data sets and ...
3
votes
1answer
363 views
Pyspark Pipeline Custom Transformer
I'm having some trouble understanding the creation of custom transformers for Pyspark pipelines.
I am writing a custom transformer that will take the dataframe column Company and remove stray commas:
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0answers
91 views
I got a overall mean average precision score of 0 for a recommendation engine
I just wanted to know if receiving an overall MAP score of 0 in a recommendation engine was possible, or a sign that my calculation or my logic for the engine was wrong.
5
votes
2answers
655 views
Model ensemble with Spark or Scikit Learn
I am using Spark MLLib to make prediction and I would like to know if it is possible to create your custom Estimators.
Here is a reproducible of what I would like my model to do with the Spark api
<...
1
vote
1answer
624 views
Getting parameters of the best model with crossvalidation in with SparkMLLib
I am having trouble accessing the parameters of estimators of model in SparkMLlib. More precisely my problem is:
I have a logistic regression model for which I want to find the best regularization ...
2
votes
2answers
678 views
K-modes implementation in pyspark
I'm looking for an implementation of k-modes in pyspark. I found this and this as implementations.
First, I tried implementing k-modes using the first link and faced issues. So I went ahead and tried ...
2
votes
0answers
64 views
Obtain learning curve of Gradient Boosted Tree model in PySpark
Currently there seems to be no method in PySpark of checkpointing the performance of a model at each gradient update. Is there a way to get the performance of a model at each gradient update so that a ...
0
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1answer
156 views
Null predictions for ALS in Pyspark
I am trying to read from my dataset which has three coloumns. (User, Repository and Number of Stars)
In[10]
...
3
votes
1answer
5k views
1
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2answers
1k views
PySpark v Pandas Dataframe Memory Issue
Suppose I have a csv file with 20k rows, which I import into Pandas dataframe. I then run models like Random Forest or Logistic Regression from sklearn package and it runs fine. However, when I import ...
2
votes
0answers
366 views
What is the difference between PySpark's featuresCol, labelCol, predictionCol, and probabilityCol?
I am attempting to train a random forest classifier (pyspark.ml.classification.RandomForestClassifier) on a large dataset (~70gb). However, I am not sure what to ...
