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https://github.com/mherrmann/helium

Lighter web automation for Python
https://github.com/mherrmann/helium

chrome firefox helium python python3 selenium selenium-python web-automation web-scraping webdriver

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Lighter web automation for Python

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# Lighter web automation with Python



Helium is a Python library for automating browsers such as Chrome and Firefox.

For example:



![Helium Demo](docs/helium-demo.gif)



## Installation



To get started with Helium, you need Python 3 and Chrome or Firefox.



I would recommend creating a virtual environment. This lets you install Helium

for just your current project, instead of globally on your whole computer.



To create and activate a virtual environment, type the following commands into

a command prompt window:



```bash

python3 -m venv venv

# On Mac/Linux:

source venv/bin/activate

# On Windows:

call venv\scripts\activate.bat

```

Then, you can install Helium with `pip`:



```bash

python -m pip install helium

```



Now enter `python` into the command prompt and (for instance) the commands in

the animation at the top of this page (`from helium import *`, ...).



## Your first script



I've compiled a [cheatsheet](docs/cheatsheet.md) that quickly teaches you all

you need to know to be productive with Helium.



## Connection to Selenium



Under the hood, Helium forwards each call to Selenium. The difference is that

Helium's API is much more high-level. In Selenium, you need to use HTML IDs,

XPaths and CSS selectors to identify web page elements. Helium on the other hand

lets you refer to elements by user-visible labels. As a result, Helium scripts

are typically 30-50% shorter than similar Selenium scripts. What's more, they

are easier to read and more stable with respect to changes in the underlying web

page.



Because Helium is simply a wrapper around Selenium, you can freely mix the two

libraries. For example:



```python

# A Helium function:

driver = start_chrome()

# A Selenium API:

driver.execute_script("alert('Hi!');")

```



So in other words, you don't lose anything by using Helium over pure Selenium.



In addition to its more high-level API, Helium simplifies further tasks that are

traditionally painful in Selenium:



- **iFrames:** Unlike Selenium, Helium lets you interact with elements inside

  nested iFrames, without having to first "switch to" the iFrame.

- **Window management.** Helium notices when popups open or close and focuses /

  defocuses them like a user would. You can also easily switch to a window by

  (parts of) its title. No more having to iterate over Selenium window handles.

- **Implicit waits.** By default, if you try click on an element with Selenium

  and that element is not yet present on the page, your script fails. Helium by

  default waits up to 10 seconds for the element to appear.

- **Explicit waits.** Helium gives you a much nicer API for waiting for a

  condition on the web page to become true. For example: To wait for an element

  to appear in Selenium, you would write:

  ```python

  element = WebDriverWait(driver, 10).until(

      EC.presence_of_element_located((By.ID, "myDynamicElement"))

  )

  ```

  With Helium, you can write:

  ```python

  wait_until(Button('Download').exists)

  ```



## Status of this project



I have too little spare time to maintain this project for free. If you'd like

my help, please go to my [web site](http://herrmann.io) to ask about my

consulting rates. Otherwise, unless it is very easy for me, I will usually not

respond to emails or issues on the issue tracker. I will however accept and

merge PRs. So if you add some functionality to Helium that may be useful for

others, do share it with us by creating a Pull Request. For instructions, please

see [Contributing](#Contributing) below.



## How you can help



I find Helium extremely useful in my own projects and feel it should be more

widely known. Here's how you can help with this:



- Star this project on GitHub.

- Tell your friends and colleagues about it.

- [Share it on Twitter with one click](https://twitter.com/intent/tweet?text=I%20find%20Helium%20very%20useful%20for%20web%20automation%20with%20Python%3A%20https%3A//github.com/mherrmann/helium)

- Share it on other social media

- Write a blog post about Helium.



With this, I think we can eventually make Helium the de-facto standard for web

automation in Python.



## Contributing



Pull Requests are very welcome. Please follow the same coding conventions as the

rest of the code, in particular the use of tabs over spaces. Also, read through my

[PR guidelines](https://gist.github.com/mherrmann/5ce21814789152c17abd91c0b3eaadca).

Doing this will save you (and me) unnecessary effort.



Before you submit a PR, ensure that the tests still work:



```bash

pip install -Ur requirements/test.txt

python setup.py test

```



This runs the tests against Chrome. To run them against Firefox, set the

environment variable `TEST_BROWSER` to `firefox`. Eg. on Mac/Linux:



```bash

TEST_BROWSER=firefox python setup.py test

```



On Windows:



```bash

set TEST_BROWSER=firefox

python setup.py test

```



If you do add new functionality, you should also add tests for it. Please see

the [`tests/`](tests) directory for what this might look like.



## History



I (Michael Herrmann) originally developed Helium in 2013 for a Polish IT startup

called BugFree software. (It could be that you have seen Helium before at

https://heliumhq.com.) We shut down the company at the end of 2019 and I felt it

would be a shame if Helium simply disappeared from the face of the earth. So I

invested some time to modernize it and bring it into a state suitable for open

source.



Helium used to be available for both Java and Python. But because I now only

use it from Python, I didn't have time to bring the Java implementation up to

speed as well. Similarly for Internet Explorer: Helium used to support it, but

since I have no need for it, I removed the (probably broken) old implementation.



The name Helium was chosen because it is also a chemical element like Selenium,

but it is lighter.