Yes, you can do this with
please explain your question what you are trying to do.
It is an expensive operation to find direct/indirect children. But have a look over this
from selenium import webdriver
driver = webdriver.Firefox()
header = driver.find_element_by_id("header")
# start from your target element, here for example, "header"
all_children_by_css = header.find_elements_by_css_selector("*")
all_children_by_xpath = header.find_elements_by_xpath(".//*")
print 'len(all_children_by_css): ' + str(len(all_children_by_css))
print 'len(all_children_by_xpath): ' + str(len(all_children_by_xpath))