SyntaxError: invalid syntax while using find_element_by_xpath using Selenium in Python

Code Trials:

from selenium import webdriver
driver = webdriver.Firefox()
driver.get("http://www.niftyindices.com/reports/historical-data")
driver.maximize_window()
driver.find_element_by_xpath("//*[@id="ddlHistorical"]").send_keys("NIFTY 100")

I am getting an error:

File "<ipython-input-32-592f058980cd>", line 5
    driver.find_element_by_xpath("//*[@id="ddlHistorical"]").send_keys("NIFTY 100")
                                                       ^
SyntaxError: invalid syntax