WebDriver路径：from selenium.webdriver.remote.webdriver import WebDriver
WebDriver内容：打开指定网页、执行js脚本、获取页面url、cook操作、多窗口及内嵌窗口的切换、窗口尺寸、窗口尺寸设置、窗口截图等
接口内容：
# Licensed to the Software Freedom Conservancy (SFC) under one
# or more contributor license agreements. See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership. The SFC licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied. See the License for the
# specific language governing permissions and limitations
# under the License.
"""The WebDriver implementation."""
import base64
import warnings
from contextlib import contextmanager
from .command import Command
from .webelement import WebElement
from .remote_connection import RemoteConnection
from .errorhandler import ErrorHandler
from .switch_to import SwitchTo
from .mobile import Mobile
from .file_detector import FileDetector, LocalFileDetector
from selenium.common.exceptions import WebDriverException
from selenium.common.exceptions import InvalidSelectorException
from selenium.webdriver.common.by import By
from selenium.webdriver.common.html5.application_cache import ApplicationCache
try:
str = basestring
except NameError:
pass
class WebDriver(object):
"""
Controls a browser by sending commands to a remote server.
This server is expected to be running the WebDriver wire protocol
as defined at
https://github.com/SeleniumHQ/selenium/wiki/JsonWireProtocol
:Attributes:
- session_id - String ID of the browser session started and controlled by this WebDriver.
- capabilities - Dictionaty of effective capabilities of this browser session as returned
by the remote server. See https://github.com/SeleniumHQ/selenium/wiki/DesiredCapabilities
- command_executor - remote_connection.RemoteConnection object used to execute commands.
- error_handler - errorhandler.ErrorHandler object used to handle errors.
"""
def __init__(self, command_executor='http://127.0.0.1:4444/wd/hub',
desired_capabilities=None, browser_profile=None, proxy=None, keep_alive=False,
file_detector=None):
"""
Create a new driver that will issue commands using the wire protocol.
:Args:
- command_executor - Either a string representing URL of the remote server or a custom
remote_connection.RemoteConnection object. Defaults to 'http://127.0.0.1:4444/wd/hub'.
- desired_capabilities - A dictionary of capabilities to request when
starting the browser session. Required parameter.
- browser_profile - A selenium.webdriver.firefox.firefox_profile.FirefoxProfile object.
Only used if Firefox is requested. Optional.
- proxy - A selenium.webdriver.common.proxy.Proxy object. The browser session will
be started with given proxy settings, if possible. Optional.
- keep_alive - Whether to configure remote_connection.RemoteConnection to use
HTTP keep-alive. Defaults to False.
- file_detector - Pass custom file detector object during instantiation. If None,
then default LocalFileDetector() will be used.
"""
if desired_capabilities is None:
raise WebDriverException("Desired Capabilities can't be None")
if not isinstance(desired_capabilities, dict):
raise WebDriverException("Desired Capabilities must be a dictionary")
if proxy is not None:
proxy.add_to_capabilities(desired_capabilities)
self.command_executor = command_executor
if type(self.command_executor) is bytes or isinstance(self.command_executor, str):
self.command_executor = RemoteConnection(command_executor, keep_alive=keep_alive)
self._is_remote = True
self.session_id = None
self.capabilities = {}
self.error_handler = ErrorHandler()
self.start_client()
self.start_session(desired_capabilities, browser_profile)
self._switch_to = SwitchTo(self)
self._mobile = Mobile(self)
self.file_detector = file_detector or LocalFileDetector()
def __repr__(self):
return '<{0.__module__}.{0.__name__} (session="{1}")>'.format(
type(self), self.session_id)
@contextmanager
def file_detector_context(self, file_detector_class, *args, **kwargs):
"""
Overrides the current file detector (if necessary) in limited context.
Ensures the original file detector is set afterwards.
Example:
with webdriver.file_detector_context(UselessFileDetector):
someinput.send_keys('/etc/hosts')
:Args:
- file_detector_class - Class of the desired file detector. If the class is different
from the current file_detector, then the class is instantiated with args and kwargs
and used as a file detector during the duration of the context manager.
- args - Optional arguments that get passed to the file detector class during
instantiation.
- kwargs - Keyword arguments, passed the same way as args.
"""
last_detector = None
if not isinstance(self.file_detector, file_detector_class):
last_detector = self.file_detector
self.file_detector = file_detector_class(*args, **kwargs)
try:
yield
finally:
if last_detector is not None:
self.file_detector = last_detector
@property
def mobile(self):
return self._mobile
@property
def name(self):
"""Returns the name of the underlying browser for this instance.
返回浏览器的名称
:Usage:
- driver.name
"""
if 'browserName' in self.capabilities:
return self.capabilities['browserName']
else:
raise KeyError('browserName not specified in session capabilities')
def start_client(self):
"""
Called before starting a new session. This method may be overridden
to define custom startup behavior.
"""
pass
def stop_client(self):
"""
Called after executing a quit command. This method may be overridden
to define custom shutdown behavior.
"""
pass
def start_session(self, desired_capabilities, browser_profile=None):
"""
Creates a new session with the desired capabilities.
:Args:
- browser_name - The name of the browser to request.
- version - Which browser version to request.
- platform - Which platform to request the browser on.
- javascript_enabled - Whether the new session should support JavaScript.
- browser_profile - A selenium.webdriver.firefox.firefox_profile.FirefoxProfile object. Only used if Firefox is requested.
"""
if browser_profile:
desired_capabilities['firefox_profile'] = browser_profile.encoded
response = self.execute(Command.NEW_SESSION, {
'desiredCapabilities': desired_capabilities,
})
self.session_id = response['sessionId']
self.capabilities = response['value']
# Quick check to see if we have a W3C Compliant browser
self.w3c = "specificationLevel" in self.capabilities
def _wrap_value(self, value):
if isinstance(value, dict):
converted = {}
for key, val in value.items():
converted[key] = self._wrap_value(val)
return converted
elif isinstance(value, WebElement):
return {'ELEMENT': value.id, 'element-6066-11e4-a52e-4f735466cecf': value.id}
elif isinstance(value, list):
return list(self._wrap_value(item) for item in value)
else:
return value
def create_web_element(self, element_id):
"""
Creates a web element with the specified element_id.
"""
return WebElement(self, element_id, w3c=self.w3c)
def _unwrap_value(self, value):
if isinstance(value, dict) and ('ELEMENT' in value or 'element-6066-11e4-a52e-4f735466cecf' in value):
wrapped_id = value.get('ELEMENT', None)
if wrapped_id:
return self.create_web_element(value['ELEMENT'])
else:
return self.create_web_element(value['element-6066-11e4-a52e-4f735466cecf'])
elif isinstance(value, list):
return list(self._unwrap_value(item) for item in value)
else:
return value
def execute(self, driver_command, params=None):
"""
Sends a command to be executed by a command.CommandExecutor.
:Args:
- driver_command: The name of the command to execute as a string.
- params: A dictionary of named parameters to send with the command.
:Returns:
The command's JSON response loaded into a dictionary object.
"""
if self.session_id is not None:
if not params:
params = {'sessionId': self.session_id}
elif 'sessionId' not in params:
params['sessionId'] = self.session_id
params = self._wrap_value(params)
response = self.command_executor.execute(driver_command, params)
if response:
self.error_handler.check_response(response)
response['value'] = self._unwrap_value(
response.get('value', None))
return response
# If the server doesn't send a response, assume the command was
# a success
return {'success': 0, 'value': None, 'sessionId': self.session_id}
def get(self, url):
"""
Loads a web page in the current browser session.
"""
self.execute(Command.GET, {'url': url})
@property
def title(self):
"""Returns the title of the current page.
:Usage:
driver.title
"""
resp = self.execute(Command.GET_TITLE)
return resp['value'] if resp['value'] is not None else ""
def find_element_by_id(self, id_):
"""Finds an element by id.
:Args:
- id\_ - The id of the element to be found.
:Usage:
driver.find_element_by_id('foo')
"""
return self.find_element(by=By.ID, value=id_)
def find_elements_by_id(self, id_):
"""
Finds multiple elements by id.
:Args:
- id\_ - The id of the elements to be found.
:Usage:
driver.find_elements_by_id('foo')
"""
return self.find_elements(by=By.ID, value=id_)
def find_element_by_xpath(self, xpath):
"""
Finds an element by xpath.
:Args:
- xpath - The xpath locator of the element to find.
:Usage:
driver.find_element_by_xpath('//div/td[1]')
"""
return self.find_element(by=By.XPATH, value=xpath)
def find_elements_by_xpath(self, xpath):
"""
Finds multiple elements by xpath.
:Args:
- xpath - The xpath locator of the elements to be found.
:Usage:
driver.find_elements_by_xpath("//div[contains(@class, 'foo')]")
"""
return self.find_elements(by=By.XPATH, value=xpath)
def find_element_by_link_text(self, link_text):
"""
Finds an element by link text.
:Args:
- link_text: The text of the element to be found.
:Usage:
driver.find_element_by_link_text('Sign In')
"""
return self.find_element(by=By.LINK_TEXT, value=link_text)
def find_elements_by_link_text(self, text):
"""
Finds elements by link text.
:Args:
- link_text: The text of the elements to be found.
:Usage:
driver.find_elements_by_link_text('Sign In')
"""
return self.find_elements(by=By.LINK_TEXT, value=text)
def find_element_by_partial_link_text(self, link_text):
"""
Finds an element by a partial match of its link text.
:Args:
- link_text: The text of the element to partially match on.
:Usage:
driver.find_element_by_partial_link_text('Sign')
"""
return self.find_element(by=By.PARTIAL_LINK_TEXT, value=link_text)
def find_elements_by_partial_link_text(self, link_text):
"""
Finds elements by a partial match of their link text.
:Args:
- link_text: The text of the element to partial match on.
:Usage:
driver.find_element_by_partial_link_text('Sign')
"""
return self.find_elements(by=By.PARTIAL_LINK_TEXT, value=link_text)
def find_element_by_name(self, name):
"""
Finds an element by name.
:Args:
- name: The name of the element to find.
:Usage:
driver.find_element_by_name('foo')
"""
return self.find_element(by=By.NAME, value=name)
def find_elements_by_name(self, name):
"""
Finds elements by name.
:Args:
- name: The name of the elements to find.
:Usage:
driver.find_elements_by_name('foo')
"""
return self.find_elements(by=By.NAME, value=name)
def find_element_by_tag_name(self, name):
"""
Finds an element by tag name.
:Args:
- name: The tag name of the element to find.
:Usage:
driver.find_element_by_tag_name('foo')
"""
return self.find_element(by=By.TAG_NAME, value=name)
def find_elements_by_tag_name(self, name):
"""
Finds elements by tag name.
:Args:
- name: The tag name the use when finding elements.
:Usage:
driver.find_elements_by_tag_name('foo')
"""
return self.find_elements(by=By.TAG_NAME, value=name)
def find_element_by_class_name(self, name):
"""
Finds an element by class name.
:Args:
- name: The class name of the element to find.
:Usage:
driver.find_element_by_class_name('foo')
"""
return self.find_element(by=By.CLASS_NAME, value=name)
def find_elements_by_class_name(self, name):
"""
Finds elements by class name.
:Args:
- name: The class name of the elements to find.
:Usage:
driver.find_elements_by_class_name('foo')
"""
return self.find_elements(by=By.CLASS_NAME, value=name)
def find_element_by_css_selector(self, css_selector):
"""
Finds an element by css selector.
:Args:
- css_selector: The css selector to use when finding elements.
:Usage:
driver.find_element_by_css_selector('#foo')
"""
return self.find_element(by=By.CSS_SELECTOR, value=css_selector)
def find_elements_by_css_selector(self, css_selector):
"""
Finds elements by css selector.
:Args:
- css_selector: The css selector to use when finding elements.
:Usage:
driver.find_elements_by_css_selector('.foo')
"""
return self.find_elements(by=By.CSS_SELECTOR, value=css_selector)
def execute_script(self, script, *args):
"""
Synchronously Executes JavaScript in the current window/frame.
:Args:
- script: The JavaScript to execute.
- *args: Any applicable arguments for your JavaScript.
:Usage:
driver.execute_script('document.title')
"""
converted_args = list(args)
return self.execute(Command.EXECUTE_SCRIPT,
{'script': script, 'args':converted_args})['value']
def execute_async_script(self, script, *args):
"""
Asynchronously Executes JavaScript in the current window/frame.
在当前窗口/帧中异步执行JavaScript。
:Args:
- script: The JavaScript to execute.
- *args: Any applicable arguments for your JavaScript.
:Usage:
driver.execute_async_script('document.title')
"""
converted_args = list(args)
return self.execute(Command.EXECUTE_ASYNC_SCRIPT,
{'script': script, 'args':converted_args})['value']
@property
def current_url(self):
"""
Gets the URL of the current page.
返回当前页面的url
:Usage:
driver.current_url
"""
return self.execute(Command.GET_CURRENT_URL)['value']
@property
def page_source(self):
"""
Gets the source of the current page.
返回当前页面的源代码
:Usage:
driver.page_source
"""
return self.execute(Command.GET_PAGE_SOURCE)['value']
def close(self):
"""
Closes the current window.
关闭当前窗口
:Usage:
driver.close()
"""
self.execute(Command.CLOSE)
def quit(self):
"""
Quits the driver and closes every associated window.
退出浏览器，关闭所有窗口
:Usage:
driver.quit()
"""
try:
self.execute(Command.QUIT)
finally:
self.stop_client()
@property
def current_window_handle(self):
"""
Returns the handle of the current window.
获取当前窗口的窗口句柄
:Usage:
driver.current_window_handle
"""
return self.execute(Command.GET_CURRENT_WINDOW_HANDLE)['value']
@property
def window_handles(self):
"""
Returns the handles of all windows within the current session.
获取所有窗口的窗口句柄
:Usage:
driver.window_handles
"""
return self.execute(Command.GET_WINDOW_HANDLES)['value']
def maximize_window(self):
"""
Maximizes the current window that webdriver is using
窗口最大化
"""
command = Command.MAXIMIZE_WINDOW
if self.w3c:
command = Command.W3C_MAXIMIZE_WINDOW
self.execute(command, {"windowHandle": "current"})
@property
def switch_to(self):
return self._switch_to
#Target Locators
def switch_to_active_element(self):
""" Deprecated use driver.switch_to.active_element
"""
warnings.warn("use driver.switch_to.active_element instead", DeprecationWarning)
return self._switch_to.active_element
def switch_to_window(self, window_name):
""" Deprecated use driver.switch_to.window
切换窗口
"""
warnings.warn("use driver.switch_to.window instead", DeprecationWarning)
self._switch_to.window(window_name)
def switch_to_frame(self, frame_reference):
""" Deprecated use driver.switch_to.frame
切换frame
"""
warnings.warn("use driver.switch_to.frame instead", DeprecationWarning)
self._switch_to.frame(frame_reference)
def switch_to_default_content(self):
""" Deprecated use driver.switch_to.default_content
切换到默认的窗口
"""
warnings.warn("use driver.switch_to.default_content instead", DeprecationWarning)
self._switch_to.default_content()
def switch_to_alert(self):
""" Deprecated use driver.switch_to.alert
切换到弹出框
"""
warnings.warn("use driver.switch_to.alert instead", DeprecationWarning)
return self._switch_to.alert
#Navigation
def back(self):
"""
Goes one step backward in the browser history.
浏览器返回
:Usage:
driver.back()
"""
self.execute(Command.GO_BACK)
def forward(self):
"""
Goes one step forward in the browser history.
浏览器前进
:Usage:
driver.forward()
"""
self.execute(Command.GO_FORWARD)
def refresh(self):
"""
Refreshes the current page.
刷新当前页面
:Usage:
driver.refresh()
"""
self.execute(Command.REFRESH)
# Options
def get_cookies(self):
"""
Returns a set of dictionaries, corresponding to cookies visible in the current session.
获取所有的cooks
:Usage:
driver.get_cookies()
"""
return self.execute(Command.GET_ALL_COOKIES)['value']
def get_cookie(self, name):
"""
Get a single cookie by name. Returns the cookie if found, None if not.
获取name对应的cook值
:Usage:
driver.get_cookie('my_cookie')
"""
cookies = self.get_cookies()
for cookie in cookies:
if cookie['name'] == name:
return cookie
return None
def delete_cookie(self, name):
"""
Deletes a single cookie with the given name.
删除指定的cook值
:Usage:
driver.delete_cookie('my_cookie')
"""
self.execute(Command.DELETE_COOKIE, {'name': name})
def delete_all_cookies(self):
"""
Delete all cookies in the scope of the session.
删除所有cook
:Usage:
driver.delete_all_cookies()
"""
self.execute(Command.DELETE_ALL_COOKIES)
def add_cookie(self, cookie_dict):
"""
Adds a cookie to your current session.
增加cook
:Args:
- cookie_dict: A dictionary object, with required keys - "name" and "value";
optional keys - "path", "domain", "secure", "expiry"
Usage:
driver.add_cookie({'name' : 'foo', 'value' : 'bar'})
driver.add_cookie({'name' : 'foo', 'value' : 'bar', 'path' : '/'})
driver.add_cookie({'name' : 'foo', 'value' : 'bar', 'path' : '/', 'secure':True})
"""
self.execute(Command.ADD_COOKIE, {'cookie': cookie_dict})
# Timeouts
def implicitly_wait(self, time_to_wait):
"""
Sets a sticky timeout to implicitly wait for an element to be found,
or a command to complete. This method only needs to be called one
time per session. To set the timeout for calls to
execute_async_script, see set_script_timeout.
全局等待，没执行一条命令的等待时间
:Args:
- time_to_wait: Amount of time to wait (in seconds)
:Usage:
driver.implicitly_wait(30)
"""
if self.w3c:
self.execute(Command.SET_TIMEOUTS,
{'ms': float(time_to_wait) * 1000, 'type':'implicit'})
else:
self.execute(Command.IMPLICIT_WAIT, {'ms': float(time_to_wait) * 1000})
def set_script_timeout(self, time_to_wait):
"""
Set the amount of time that the script should wait during an
execute_async_script call before throwing an error.
:Args:
- time_to_wait: The amount of time to wait (in seconds)
:Usage:
driver.set_script_timeout(30)
"""
if self.w3c:
self.execute(Command.SET_TIMEOUTS,
{'ms': float(time_to_wait) * 1000, 'type':'script'})
else:
self.execute(Command.SET_SCRIPT_TIMEOUT,
{'ms': float(time_to_wait) * 1000})
def set_page_load_timeout(self, time_to_wait):
"""
Set the amount of time to wait for a page load to complete
before throwing an error.
:Args:
- time_to_wait: The amount of time to wait
:Usage:
driver.set_page_load_timeout(30)
"""
self.execute(Command.SET_TIMEOUTS,
{'ms': float(time_to_wait) * 1000, 'type':'page load'})
def find_element(self, by=By.ID, value=None):
"""
'Private' method used by the find_element_by_* methods.
:Usage:
Use the corresponding find_element_by_* instead of this.
:rtype: WebElement
"""
if not By.is_valid(by) or not isinstance(value, str):
raise InvalidSelectorException("Invalid locator values passed in")
if self.w3c:
if by == By.ID:
by = By.CSS_SELECTOR
value = '[id="%s"]' % value
elif by == By.TAG_NAME:
by = By.CSS_SELECTOR
elif by == By.CLASS_NAME:
by = By.CSS_SELECTOR
value = ".%s" % value
elif by == By.NAME:
by = By.CSS_SELECTOR
value = '[name="%s"]' % value
return self.execute(Command.FIND_ELEMENT,
{'using': by, 'value': value})['value']
def find_elements(self, by=By.ID, value=None):
"""
'Private' method used by the find_elements_by_* methods.
:Usage:
Use the corresponding find_elements_by_* instead of this.
:rtype: list of WebElement
"""
if not By.is_valid(by) or not isinstance(value, str):
raise InvalidSelectorException("Invalid locator values passed in")
if self.w3c:
if by == By.ID:
by = By.CSS_SELECTOR
value = '[id="%s"]' % value
elif by == By.TAG_NAME:
by = By.CSS_SELECTOR
elif by == By.CLASS_NAME:
by = By.CSS_SELECTOR
value = ".%s" % value
elif by == By.NAME:
by = By.CSS_SELECTOR
value = '[name="%s"]' % value
return self.execute(Command.FIND_ELEMENTS,
{'using': by, 'value': value})['value']
@property
def desired_capabilities(self):
"""
returns the drivers current desired capabilities being used
"""
return self.capabilities
def get_screenshot_as_file(self, filename):
"""
Gets the screenshot of the current window. Returns False if there is
any IOError, else returns True. Use full paths in your filename.
:Args:
- filename: The full path you wish to save your screenshot to.
:Usage:
driver.get_screenshot_as_file('/Screenshots/foo.png')
"""
png = self.get_screenshot_as_png()
try:
with open(filename, 'wb') as f:
f.write(png)
except IOError:
return False
finally:
del png
return True
save_screenshot = get_screenshot_as_file
def get_screenshot_as_png(self):
"""
Gets the screenshot of the current window as a binary data.
:Usage:
driver.get_screenshot_as_png()
"""
return base64.b64decode(self.get_screenshot_as_base64().encode('ascii'))
def get_screenshot_as_base64(self):
"""
Gets the screenshot of the current window as a base64 encoded string
which is useful in embedded images in HTML.
:Usage:
driver.get_screenshot_as_base64()
"""
return self.execute(Command.SCREENSHOT)['value']
def set_window_size(self, width, height, windowHandle='current'):
"""
Sets the width and height of the current window. (window.resizeTo)
:Args:
- the width in pixels to set the window to
- height: the height in pixels to set the window to
:Usage:
driver.set_window_size(800,600)
"""
command = Command.SET_WINDOW_SIZE
if self.w3c:
command = Command.W3C_SET_WINDOW_SIZE
self.execute(command, {'width': int(width), 'height': int(height),
'windowHandle': windowHandle})
def get_window_size(self, windowHandle='current'):
"""
Gets the width and height of the current window.
:Usage:
driver.get_window_size()
"""
command = Command.GET_WINDOW_SIZE
if self.w3c:
command = Command.W3C_GET_WINDOW_SIZE
size = self.execute(command,
{'windowHandle': windowHandle})
if size.get('value', None) != None:
return size['value']
else:
return size
def set_window_position(self, x, y, windowHandle='current'):
"""
Sets the x,y position of the current window. (window.moveTo)
:Args:
- x: the x-coordinate in pixels to set the window position
- y: the y-coordinate in pixels to set the window position
:Usage:
driver.set_window_position(0,0)
"""
self.execute(Command.SET_WINDOW_POSITION, {'x': int(x), 'y': int(y),
'windowHandle': windowHandle})
def get_window_position(self, windowHandle='current'):
"""
Gets the x,y position of the current window.
:Usage:
driver.get_window_position()
"""
return self.execute(Command.GET_WINDOW_POSITION,
{'windowHandle': windowHandle})['value']
@property
def file_detector(self):
return self._file_detector
@file_detector.setter
def file_detector(self, detector):
"""
Set the file detector to be used when sending keyboard input.
By default, this is set to a file detector that does nothing.
see FileDetector
see LocalFileDetector
see UselessFileDetector
:Args:
- detector: The detector to use. Must not be None.
"""
if detector == None:
raise WebDriverException("You may not set a file detector that is null")
if not isinstance(detector, FileDetector):
raise WebDriverException("Detector has to be instance of FileDetector")
self._file_detector = detector;
@property
def orientation(self):
"""
Gets the current orientation of the device
:Usage:
orientation = driver.orientation
"""
return self.execute(Command.GET_SCREEN_ORIENTATION)['value']
@orientation.setter
def orientation(self, value):
"""
Sets the current orientation of the device
:Args:
- value: orientation to set it to.
:Usage:
driver.orientation = 'landscape'
"""
allowed_values = ['LANDSCAPE', 'PORTRAIT']
if value.upper() in allowed_values:
self.execute(Command.SET_SCREEN_ORIENTATION, {'orientation': value})
else:
raise WebDriverException("You can only set the orientation to 'LANDSCAPE' and 'PORTRAIT'")
@property
def application_cache(self):
""" Returns a ApplicationCache Object to interact with the browser app cache"""
return ApplicationCache(self)
@property
def log_types(self):
"""
Gets a list of the available log types
:Usage:
driver.log_types
"""
return self.execute(Command.GET_AVAILABLE_LOG_TYPES)['value']
def get_log(self, log_type):
"""
Gets the log for a given log type
:Args:
- log_type: type of log that which will be returned
:Usage:
driver.get_log('browser')
driver.get_log('driver')
driver.get_log('client')
driver.get_log('server')
"""
return self.execute(Command.GET_LOG, {'type': log_type})['value']