selenium click a span tag

[snippsat]

Do not do any loop,before you have tested that it work on first span tag.

Code under will return the first match of span tag,
make sure that this is the right span tag(can be more in source).

browser.find_element_by_tag_name("span")

Can return a list so test with:

browser.find_element_by_tag_name("span")[0].click()

Try with a more excat mact(CSS selector/xPath) to "span" tag you want to test click on.
Edit:
And lower case in .Click(),so .click()