csv

问题 I am trying to process large csv data in nodejs at server side, but as node is single threaded cpu uses goes to 100%. I could not find any solution so that it does not consume much time. So I have decided to process the data on client side and then send it to server and then save it into database. The data might be about 20 to 30 MB. Is it possible or if possible is it good practice to send this much data over http. I checked this question but could not find it helpful. 回答1: To know the limit

问题 I am trying to process large csv data in nodejs at server side, but as node is single threaded cpu uses goes to 100%. I could not find any solution so that it does not consume much time. So I have decided to process the data on client side and then send it to server and then save it into database. The data might be about 20 to 30 MB. Is it possible or if possible is it good practice to send this much data over http. I checked this question but could not find it helpful. 回答1: To know the limit

问题 What is the best way to read a csv formatted result from a rest api directly into spark? Basically have this which I know I can process in scala and save to a file but would like to process the data in spark: val resultCsv = scala.io.Source.fromURL(url).getLines() 回答1: This is how it can be done. For Spark 2.2.x import scala.io.Source._ import org.apache.spark.sql.{Dataset, SparkSession} var res = fromURL(url).mkString.stripMargin.lines.toList val csvData: Dataset[String] = spark.sparkContext

问题 What is the best way to read a csv formatted result from a rest api directly into spark? Basically have this which I know I can process in scala and save to a file but would like to process the data in spark: val resultCsv = scala.io.Source.fromURL(url).getLines() 回答1: This is how it can be done. For Spark 2.2.x import scala.io.Source._ import org.apache.spark.sql.{Dataset, SparkSession} var res = fromURL(url).mkString.stripMargin.lines.toList val csvData: Dataset[String] = spark.sparkContext

问题 Context : I have a Post Mongoose model that contains a csv_files array field to store csv strings. I make a fetch API request from a different web app to POST the csv strings for a particular Post . The code below produces an error UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 2): VersionError: No matching document found for id "5966932399e969ad8013bedf" router.js router.post('/posts/:url/upload-csv/:csv_name', (req, res) => { let csv_name = req.params.csv_name;

问题 Context : I have a Post Mongoose model that contains a csv_files array field to store csv strings. I make a fetch API request from a different web app to POST the csv strings for a particular Post . The code below produces an error UnhandledPromiseRejectionWarning: Unhandled promise rejection (rejection id: 2): VersionError: No matching document found for id "5966932399e969ad8013bedf" router.js router.post('/posts/:url/upload-csv/:csv_name', (req, res) => { let csv_name = req.params.csv_name;

问题 Using matplotlib/pandas/python, I cannot visualize data as values per 30mins and per days is a new question, which is strongly related to this question. I want to visualize CSV data with Matplotlib. Following is my code named 1.30mins.py import matplotlib.pyplot as plt from matplotlib import style import numpy as np style.use('ggplot') x,y =np.loadtxt('total_watt.csv', unpack = True, delimiter = ',') plt.plot(x,y) plt.title('Example') plt.ylabel('Y axis') plt.xlabel('X axis') plt.show() When

问题 Using matplotlib/pandas/python, I cannot visualize data as values per 30mins and per days is a new question, which is strongly related to this question. I want to visualize CSV data with Matplotlib. Following is my code named 1.30mins.py import matplotlib.pyplot as plt from matplotlib import style import numpy as np style.use('ggplot') x,y =np.loadtxt('total_watt.csv', unpack = True, delimiter = ',') plt.plot(x,y) plt.title('Example') plt.ylabel('Y axis') plt.xlabel('X axis') plt.show() When

问题 Using matplotlib/pandas/python, I cannot visualize data as values per 30mins and per days is a new question, which is strongly related to this question. I want to visualize CSV data with Matplotlib. Following is my code named 1.30mins.py import matplotlib.pyplot as plt from matplotlib import style import numpy as np style.use('ggplot') x,y =np.loadtxt('total_watt.csv', unpack = True, delimiter = ',') plt.plot(x,y) plt.title('Example') plt.ylabel('Y axis') plt.xlabel('X axis') plt.show() When

问题 I'm reading data from a csv file. I get that 'row' is the variable that represents the loop I am going through, but what is the "_" that is being thrown away here? for row in csv_reader: _, Student.objects.get_or_create( first_name=row[0], last_name=row[1], email=row[2], organisation=row[3], enrolled=row[4], last_booking=row[5], credits_total=row[6], credits_balance=row[7], ) For example, this code also works: for row in csv_reader: Student.objects.get_or_create( first_name=row[0], last_name