A quick and practical guide about how to debug Scrapy projects using PyCharm.

My setup is:

  • Scrapy 1.6.0
  • Python 3.6
  • PyCharm Community Edition 2019.2
  • virtualenv
  • Linux Mint 19

This turial should work find for older scrapy/python version and for Windows/MacOS.

Note: You can find introduction tutorial for scrapy on this page: Python scrapy tutorial for beginners

Run Scrapy spider from PyCharm terminal

The optimal way for running scrapy spiders is by using terminal because:

  • a lot useful information is shown
  • you have control on the process
  • needs of customization - batching, scheduling, output files - csv, json

In order to run a spider using the PyCharm terminal you can do:

  • Open the PyCharm project
  • Open terminal dialog - ALT + F12
  • Navigate in terminal to spider file (you can check the image below)
  • Start spider with command
    • just for running and getting output in terminal window - scrapy runspider CoinMarketCap.py
    • to collect the results as csv file - scrapy runspider CoinMarketCap.py -o coins.csv

For simple spiders like the one above this will be enough. For more complex spiders and websites you will need to find why some data is not scraped or your spider stop scraping when you expect more data. This is when debugging come to rescue.

PyCharm_Scrapy_runspider

Setup configuration for Scrapy debug

Again you will need to open your PyCharm project and spider be prepared. Once you have them you can continue with next steps:

  • locate the file in Project browser
  • Open the file
  • Add breakpoint to the line of your interest
  • Run the python file - Shift + F10 - in order to add configuration or you can add it later
  • Open Run/Debug Configurations
    • top right corner - next to run button
    • Main Menu / Run / Edit Configurations
  • Change Script path to Module name
    • enter scrapy.cmdline
  • In Parameters
    • runspider CoinMarketCap.py
  • Apply and OK

This configuration is working since PyCharm 2018 for older versions you will need to do:

  • Open Run/Debug Configurations
  • Enter Scrith path
    • locate you scrapy file in the virtual environment or by using which scrapy
    • enter the full path - /home/vanx/Software/Tensorflow/environments/venv36/bin/scrapy
  • In Parameters
    • runspider CoinMarketCap.py

Now you can debug the spider.

PyCharm_Scrapy_configuration

Additional notes and tips for Scrapy/PyCharm debugging

Scrapy/PyCharm debugging tips

  • In order to debug efficiently you can use Evaluate expression feature of PyCharm - Alt + F8 or right click on selected code
  • Use Conditional breakpoints - in order to avoid long debugging sessions with Step Over and Step In
  • If you more info for PyCharm/IntelliJ debugging - IntelliJ Debug, conditional breakpoints and step back

Note:

There are several commands which can be used:

  • scrapy
  • runspider
  • crawl

all of them are python scripts which means they can be started from terminal or by Pycharm setup above.

In order to see all available commands for module scrapy you can type in PyCharm terminal:

$ scrapy

Result:

Scrapy 1.6.0 - no active project

Usage:
  scrapy <command> [options] [args]

Available commands:
  bench         Run quick benchmark test
  fetch         Fetch a URL using the Scrapy downloader
  genspider     Generate new spider using pre-defined templates
  runspider     Run a self-contained spider (without creating a project)
  settings      Get settings values
  shell         Interactive scraping console
  startproject  Create new project
  version       Print Scrapy version
  view          Open URL in browser, as seen by Scrapy

  [ more ]      More commands available when run from project directory

Use "scrapy <command> -h" to see more info about a command

And this is the output if you run it from explicit scrapy project:

Scrapy 1.6.0 - project: quotesbot

Usage:
  scrapy <command> [options] [args]

Available commands:
  bench         Run quick benchmark test
  check         Check spider contracts
  crawl         Run a spider
  edit          Edit spider
  fetch         Fetch a URL using the Scrapy downloader
  genspider     Generate new spider using pre-defined templates
  list          List available spiders
  parse         Parse URL (using its spider) and print the results
  runspider     Run a self-contained spider (without creating a project)
  settings      Get settings values
  shell         Interactive scraping console
  startproject  Create new project
  version       Print Scrapy version
  view          Open URL in browser, as seen by Scrapy

Use "scrapy <command> -h" to see more info about a command

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