I have a text widget in which user needs to feed in batch id say "201906", it is a year with month. So the data gets processed for this particular batch. So now how do I get this value from a CSV or a file name located in ADLS container and use it in a databricks dropdown widget so that the user will not have the freedom to enter a batchid which is not to be processed or restricted to process? So basically I want to give the option to the user with the required batch to be processed but not an entire field to type whatever he wants.
It's just easy - you can use local file API to access file on DBFS, like this (you need to replace dbfs:/ with /dbfs/ to access file on DBFS):
with open("/dbfs/tmp/my-batches.txt") as f:
batches = [l.strip() for l in f.readlines() if l.strip() != ""]
dbutils.widgets.dropdown(name="batches", label="Select batch",
choices=batches, defaultValue=batches[0])
will give you what you need:
You can achieve the same by using the Spark API - it could be a bit slower, but it won't require that storage account is mounted - you can use abfss://, wasbs:// and other supported protocols:
dbutils.widgets.removeAll()
df = spark.read.text("/tmp/my-batches.txt")
batches = [r[0].strip() for r in df.collect() if r[0].strip() != ""]
dbutils.widgets.dropdown(name="batches", label="Select batch",
choices=batches, defaultValue=batches[0])
Related
I have a dataset which have an xml column and i am trying to export individual xmls as files with filename being in another column using codeworkbook
I filtered the rows i want using below code
def prepare_input(xml_with_debug):
from pyspark.sql import functions as F
filter_column = "key"
filter_value = "test_key"
df_filtered = xml_with_debug.filter(filter_value == F.col(filter_column))
approx_number_of_rows = 1
sample_percent = float(approx_number_of_rows) / df_filtered.count()
df_sampled = df_filtered.sample(False, sample_percent, seed=0)
important_columns = ["key", "xml"]
return df_sampled.select([F.col(c).cast(F.StringType()).alias(c) for c in important_columns])
It works till here. Now for the last part i tried this in a python task, but was complaining about the parameters (i should have set it up wrongly). But even if it works it will be as a single file i think.
from transforms.api import transform, Input, Output
#transform(
output=Output("/path/to/python_csv"),
my_input=Input("/path/to/input")
)
def my_compute_function(output, my_input):
output.write_dataframe(my_input.dataframe().coalesce(1), output_format="csv", options={"header": "true"})
I am trying to set it up in GUI like below
My question i guess is, what will be the code in the last Python task (write_file) after the prepare input so that i extract individual xmls (And if possible zip them into single file for download)
You can access the output dataset filesystem and write files into it in whatever format you want.
The documentation for that can be found here: https://www.palantir.com/docs/foundry/code-workbook/transforms-unstructured/#writing-files
(If you want to do it from a code repository it's very similar https://www.palantir.com/docs/foundry/transforms-python/unstructured-files/#writing-files)
By doing that you can create multiple different files or you can create a single zip file and write it into a dataset.
I am using Paraview to display well log information stored in csv files.
Upon loading the csv data file and adding the "Table to Points" filter, I manually specify which columns should be used for the X Column, Y Column and Z Column (e.g. I am using a column called "Easting" for the "X Column").
Is there a way to automate this step? Maybe some kind of configuration file that could be fed into Paraview to indicate the column mapping?
You can use python macro to do that. Macros in ParaView are python script you can trigger from the toolbar.
You can use this one to create and configure a TableToPoints filter (with modif according to your column names):
#### import the simple module from the paraview
from paraview.simple import *
#### disable automatic camera reset on 'Show'
paraview.simple._DisableFirstRenderCameraReset()
# create a new 'Table To Points'
tableToPoints1 = TableToPoints(registrationName='TableToPoints1')
# configure column names
tableToPoints1.XColumn = 'y1'
tableToPoints1.YColumn = 'y2'
tableToPoints1.ZColumn = 'y26'
# get active view
spreadSheetView1 = GetActiveViewOrCreate('SpreadSheetView')
# show data in view
tableToPoints1Display = Show(tableToPoints1, spreadSheetView1, 'SpreadSheetRepresentation')
# hide data in view
Hide(sineWavescsv, spreadSheetView1)
# update the view to ensure updated data information
spreadSheetView1.Update()
Store it on your disk and go to menu Macros / Import new macro
Note that you can easily create your own with the Python Trace:
menu Tools / Start Trace (with default options)
perform the actions you want to replay later (load file, create filters, edit color map, ...)
Tools / Stop Trace. It opens an editor with python code, you can save it as a macro.
The macro is a new button in the toolbar.
I have a data feed that gives a large .txt file (50-75GB) every day. The file contains several different schemas within it, where each row corresponds to one schema. I would like to split this into partitioned datasets for each schema, how can I do this efficiently?
The largest problem you need to solve is the iteration speed to recover your schemas, which can be challenging for a file at this scale.
Your best tactic here will be to get an example 'notional' file with each of the schemas you want to recover as a line within it, and to add this as a file within your repository. When you add this file into your repo (alongside your transformation logic), you will then be able to push it into a dataframe, much as you would with the raw files in your dataset, for quick testing iteration.
First, make sure you specify txt files as a part of your package contents, this way your tests will discover them (this is covered in documentation under Read a file from a Python repository):
You can read other files from your repository into the transform context. This might be useful in setting parameters for your transform code to reference.
To start, In your python repository edit setup.py:
setup(
name=os.environ['PKG_NAME'],
# ...
package_data={
'': ['*.txt']
}
)
I am using a txt file with the following contents:
my_column, my_other_column
some_string,some_other_string
some_thing,some_other_thing,some_final_thing
This text file is at the following path in my repository: transforms-python/src/myproject/datasets/raw.txt
Once you have configured the text file to be shipped with your logic, and after you have included the file itself in your repository, you can then include the following code. This code has a couple of important functions:
It keeps raw file parsing logic completely separate from the stage of reading the file into a Spark DataFrame. This is so that the way this DataFrame is constructed can be left to the test infrastructure, or to the run time, depending on where you are running.
This keeping of the logic separate lets you ensure the actual row-by-row parsing you want to do is its own testable function, instead of having it live purely within your my_compute_function
This code uses the Spark-native spark_session.read.text method, which will be orders of magnitude faster than row-by-row parsing of a raw txt file. This will ensure the parallelized DataFrame is what you operate on, not a single file, line by line, inside your executors (or worse, your driver).
from transforms.api import transform, Input, Output
from pkg_resources import resource_filename
def raw_parsing_logic(raw_df):
return raw_df
#transform(
my_output=Output("/txt_tests/parsed_files"),
my_input=Input("/txt_tests/dataset_of_files"),
)
def my_compute_function(my_input, my_output, ctx):
all_files_df = None
for file_status in my_input.filesystem().ls('**/**'):
raw_df = ctx.spark_session.read.text(my_input.filesystem().hadoop_path + "/" + file_status.path)
parsed_df = raw_parsing_logic(raw_df)
all_files_df = parsed_df if all_files_df is None else all_files_df.unionByName(parsed_df)
my_output.write_dataframe(all_files_df)
def test_my_compute_function(spark_session):
file_path = resource_filename(__name__, "raw.txt")
raw_df = raw_parsing_logic(
spark_session.read.text(file_path)
)
assert raw_df.count() > 0
raw_columns_set = set(raw_df.columns)
expected_columns_set = {"value"}
assert len(raw_columns_set.intersection(expected_columns_set)) == 1
Once you have this code up and running, your test_my_compute_function method will be very fast to iterate on, so that you can perfect your schema recovery logic. This will make it substantially easier to get your dataset building at the very end, but without any of the overhead of a full build.
When I run my PsychoPy experiment, PsychoPy saves a CSV file that contains my trials and the values of my variables.
Among these, there are some variables I would like to NOT be included. There are some variables which I decided to include in the CSV, but many others which automatically felt in it.
is there a way to manually force (from the code block) the exclusion of some variables in the CSV?
is there a way to decide the order of the saved columns/variables in the CSV?
It is not really important and I know I could just create myself an output file without using the one of PsychoPy, or I can easily clean it afterwards but I was just curious.
PsychoPy spits out all the variables it thinks you could need. If you want to drop some of them, that is a task for the analysis stage, and is easily done in any processing pipeline. Unless you are analysing data in a spreadsheet (which you really shouldn't), the number of columns in the output file shouldn't really be an issue. The philosophy is that you shouldn't back yourself into a corner by discarding data at the recording stage - what about the reviewer who asks about the influence of a variable that you didn't think was important?
If you are using the Builder interface, the saving of onset & offset times for each component is optional, and is controlled in the "data" tab of each component dialog.
The order of variables is also not under direct control of the user, but again, can be easily manipulated at the analysis stage.
As you note, you can of course write code to save custom output files of your own design.
there is a special block called session_variable_order: [var1, var2, var3] in experiment_config.yaml file, which you probably should be using; also, you should consider these methods:
from psychopy import data
data.ExperimentHandler.saveAsWideText(fileName = 'exp_handler.csv', delim='\t', sortColumns = False, encoding = 'utf-8')
data.TrialHandler.saveAsText(fileName = 'trial_handler.txt', delim=',', encoding = 'utf-8', dataOut = ('n', 'all_mean', 'all_raw'), summarised = False)
notice the sortColumns and dataOut params
I am new to CouchDB. I need to get 60 or more JSON files in a minute from a server.
I have to upload these JSON files to CouchDB individually as soon as I receive them.
I installed CouchDB on my Linux machine.
I hope some one can help me with my requirement.
If possible can someone help me with pseudo code.
My Idea:
Is to write a python script for uploading all JSON files to CouchDB.
Each and every JSON file must be each document and the data present in
JSON must be inserted same into CouchDB
(the specified format with values in a file).
Note:
These JSON files are Transactional, every second 1 file is generated
so I need to read the file upload as same format into CouchDB on
successful uploading archive the file into local system of different folder.
python program to parse the json and insert into CouchDb:
import sys
import glob
import errno,time,os
import couchdb,simplejson
import json
from pprint import pprint
couch = couchdb.Server() # Assuming localhost:5984
#couch.resource.credentials = (USERNAME, PASSWORD)
# If your CouchDB server is running elsewhere, set it up like this:
couch = couchdb.Server('http://localhost:5984/')
db = couch['mydb']
path = 'C:/Users/Desktop/CouchDB_Python/Json_files/*.json'
#dirPath = 'C:/Users/VijayKumar/Desktop/CouchDB_Python'
files = glob.glob(path)
for file1 in files:
#dirs = os.listdir( dirPath )
file2 = glob.glob(file1)
for name in file2: # 'file' is a builtin type, 'name' is a less-ambiguous variable name.
try:
with open(name) as f: # No need to specify 'r': this is the default.
#sys.stdout.write(f.read())
json_data=f
data = json.load(json_data)
db.save(data)
pprint(data)
json_data.close()
#time.sleep(2)
except IOError as exc:
if exc.errno != errno.EISDIR: # Do not fail if a directory is found, just ignore it.
raise # Propagate other kinds of IOError.
I would use CouchDB bulk API, even though you have specified that you need to send them to db one by one. For example, by implementing a simple queue that gets sent out every say 5 - 10 seconds via a bulk doc call will greatly increase performance of your application.
There is obviously a quirk in that and that is you need to know the IDs of the docs that you want to get from the DB. But for the PUTs it is perfect. (it is not entirely true, you can get ranges of docs using bulk operation if the IDs you are using for your docs can be sorted nicely).
From my experience working with CouchDB, I have a hunch that you are dealing with Transactional documents in order to compile them into some sort of sum result and act on that data accordingly (maybe creating next transactional doc in series). For that you can rely on CouchDB by using 'reduce' functions on the views you create. It takes a little practice to get reduce function working properly and is highly dependent on what it is you actually what to achieve and what data you are prepared to emit by the view so I can't really provide you with more detail on that.
So in the end the app logic would go something like that:
get _design/someDesign/_view/yourReducedView
calculate new transaction
add transaction to queue
onTimeout
send all in transaction queue
If I got that first part of why you are using transactional docs wrong all that would really change is the part where you getting those transactional docs in my app logic.
Also, before writing your own 'reduce' function, have a look at buil-in ones (they are alot faster then anything outside of db engine can do)
http://wiki.apache.org/couchdb/HTTP_Bulk_Document_API
EDIT:
Since you are starting, I strongly recommend to have a look at CouchDB Definitive Guide.
NOTE FOR LATER:
Here is one hidden stone (well maybe not so much a hidden stone but not an obvious thing to look out for for the new-comer in any case). When you write reduce function make sure that it does not produce too much output for the query without boundaries. This will extremely slow down the entire view even when you provide reduce=false when getting stuff from it.
So you need to get JSON documents from a server and send them to CouchDB as you receive them. A Python script would work fine. Here is some pseudo-code:
loop (until no more docs)
get new JSON doc from server
send JSON doc to CouchDB
end loop
In Python, you could use requests to send the documents to CouchDB and probably to get the documents from the server as well (if it is using an HTTP API).
You might want to checkout the pycouchdb module for python3. I've used it myself to upload lots of JSON objects into couchdb instance. My project does pretty much the same as you describe so you can take a look at my project Pyro at Github for details.
My class looks like that:
class MyCouch:
""" COMMUNICATES WITH COUCHDB SERVER """
def __init__(self, server, port, user, password, database):
# ESTABLISHING CONNECTION
self.server = pycouchdb.Server("http://" + user + ":" + password + "#" + server + ":" + port + "/")
self.db = self.server.database(database)
def check_doc_rev(self, doc_id):
# CHECKS REVISION OF SUPPLIED DOCUMENT
try:
rev = self.db.get(doc_id)
return rev["_rev"]
except Exception as inst:
return -1
def update(self, all_computers):
# UPDATES DATABASE WITH JSON STRING
try:
result = self.db.save_bulk( all_computers, transaction=False )
sys.stdout.write( " Updating database" )
sys.stdout.flush()
return result
except Exception as ex:
sys.stdout.write( "Updating database" )
sys.stdout.write( "Exception: " )
print( ex )
sys.stdout.flush()
return None
Let me know in case of any questions - I will be more than glad to help if you will find some of my code usable.