delver 0.1.2

Modern user friendly web automation and scraping library.

Delver
========================

Programmatic web browser/crawler in Python. **Alternative to Mechanize, RoboBrowser, MechanicalSoup**
and others. Strict power of Request and Lxml. Some features and methods usefull in scraping "out of the box".

- [Basic examples](#basic-examples)
- [Form submit](#form-submit)
- [Find links narrowed by filters](#find-links-narrowed-by-filters)
- [Download file](#download-file)
- [Download files list in parallel](#download-files-list-in-parallel)
- [Xpath selectors](#xpath-selectors)
- [Css selectors](#css-selectors)
- [Xpath result with filters](#xpath-result-with-filters)
- [Use examples](#use-examples)
- [Scraping Steam Specials using XPath](#scraping-steam-specials-using-xpath)
- [Simple tables scraping out of the box](#simple-tables-scraping-out-of-the-box)
- [User login](#user-login)
- [One Punch Man Downloader](#one-punch-man-downloader)

- - -

## Basic examples


## Form submit

```python

>>> from delver import Crawler
>>> c = Crawler()
>>> response = c.open('https://httpbin.org/forms/post')
>>> forms = c.forms()

# Filling up fields values:
>>> form = forms[0]
>>> form.fields = {
... 'custname': 'Ruben Rybnik',
... 'custemail': '[e-mail]',
... 'size': 'medium',
... 'topping': ['bacon', 'cheese'],
... 'custtel': '[phone]'
... }
>>> submit_result = c.submit(form)
>>> submit_result.status_code
200

# Checking if form post ended with success:
>>> c.submit_check(
... form,
... phrase="Ruben Rybnik",
... url='https://httpbin.org/forms/post',
... status_codes=[200]
... )
True
```

## Find links narrowed by filters

```python

>>> c = Crawler()
>>> c.open('https://httpbin.org/links/10/0')
<Response [200]>

# Links can be filtered by some html tags and filters
# like: id, text, title and class:
>>> links = c.links(
... tags = ('style', 'link', 'script', 'a'),
... filters = {
... 'text': '7'
... },
... match='NOT_EQUAL'
... )
>>> len(links)
8
```

## Download file

```python

>>> import os

>>> c = Crawler()
>>> local_file_path = c.download(
... local_path='test',
... url='https://httpbin.org/image/png',
... name='test.png'
... )
>>> os.path.isfile(local_file_path)
True
```

## Download files list in parallel

```python

>>> c = Crawler()
>>> c.open('https://xkcd.com/')
<Response [200]>
>>> full_images_urls = [c.join_url(src) for src in c.images()]
>>> downloaded_files = c.download_files('test', files=full_images_urls)
>>> len(full_images_urls) == len(downloaded_files)
True
```

## Xpath selectors

```python

c = Crawler()
c.open('https://httpbin.org/html')
p_text = c.xpath('//p/text()')
```

## Css selectors

```python

c = Crawler()
c.open('https://httpbin.org/html')
p_text = c.css('div')
```

## Xpath result with filters

```python

c = Crawler()
c.open('https://www.w3schools.com/')
filtered_results = c.xpath('//p').filter(filters={'class': 'w3-xlarge'})
```

## Using retries

```python

c = Crawler()
# sets max_retries to 2 means that after there will be max two attempts to open url
# if first attempt will fail, wait 1 second and try again, second attempt wait 2 seconds
# and then try again
c.max_retries = 2
c.open('http://www.delver.cg/404')
```

## Use examples


## Scraping Steam Specials using XPath

```python

from pprint import pprint
from delver import Crawler

c = Crawler(absolute_links=True)
c.logging = True
c.useragent = "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"
c.random_timeout = (0, 5)
c.open('http://store.steampowered.com/search/?specials=1')
titles, discounts, final_prices = [], [], []


while c.links(filters={
'class': 'pagebtn',
'text': '>'
}):
c.open(c.current_results[0])
titles.extend(
c.xpath("//div/span[@class='title']/text()")
)
discounts.extend(
c.xpath("//div[contains(@class, 'search_discount')]/span/text()")
)
final_prices.extend(
c.xpath("//div[contains(@class, 'discounted')]//text()[2]").strip()
)

all_results = {
row[0]: {
'discount': row[1],
'final_price': row[2]
} for row in zip(titles, discounts, final_prices)}
pprint(all_results)
```

## Simple tables scraping out of the box

```python

from pprint import pprint
from delver import Crawler

c = Crawler(absolute_links=True)
c.logging = True
c.useragent = "Mozilla/5.0 (compatible; Googlebot/2.1; +http://www.google.com/bot.html)"
c.open("http://www.boxofficemojo.com/daily/")
pprint(c.tables())
```

## User login

```python


from delver import Crawler

c = Crawler()
c.useragent = (
"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) "
"Chrome/60.0.3112.90 Safari/537.36"
)
c.random_timeout = (0, 5)
c.open('http://testing-ground.scraping.pro/login')
forms = c.forms()
if forms:
login_form = forms[0]
login_form.fields = {
'usr': 'admin',
'pwd': '12345'
}
c.submit(login_form)
success_check = c.submit_check(
login_form,
phrase='WELCOME :)',
status_codes=[200]
)
print(success_check)
```

## One Punch Man Downloader

```python

import os
from delver import Crawler

class OnePunchManDownloader:
"""Downloads One Punch Man free manga chapers to local directories.
Uses one main thread for scraper with random timeout.
Uses 20 threads just for image downloads.
"""
def __init__(self):
self._target_directory = 'one_punch_man'
self._start_url = "http://m.mangafox.me/manga/onepunch_man_one/"
self.crawler = Crawler()
self.crawler.random_timeout = (0, 5)
self.crawler.useragent = "Googlebot-Image/1.0"

def run(self):
self.crawler.open(self._start_url)
for link in self.crawler.links(filters={'text': 'Ch '}, match='IN'):
self.download_images(link)

def download_images(self, link):
target_path = '{}/{}'.format(self._target_directory, link.split('/')[-2])
full_chapter_url = link.replace('/manga/', '/roll_manga/')
self.crawler.open(full_chapter_url)
images = self.crawler.xpath("//img[@class='reader-page']/@data-original")
os.makedirs(target_path, exist_ok=True)
self.crawler.download_files(target_path, files=images, workers=20)


downloader = OnePunchManDownloader()
downloader.run()
```


=======
History
=======

0.1.1 (2017-09-25)
------------------

* First release on PyPI.