我的應用str.format
對於my_xpath
下面有什麼問題?如何通過函數傳遞多個字符串到str.format()
def look_for(thing, value):
my_xpath = "//h2[. = '{thing_placeholder}']/following::table//td[. = '{value_placeholder}']"
my_xpath.format(thing, value)
return my_xpath
look_for("MyThing", "MyValue")
...這是行不通的,而不是拋出一個KeyError
時my_xpath
應用於找到一個網絡元素。
或者,如果我嘗試這個變體,而不是,這不是抱怨KeyError異常,但我發現None
回:
def look_for_v2(thing, value):
my_xpath = "//h2[. = '{thing_placeholder}']/following::table//td[. = '{value_placeholder}']"
my_xpath.format(thing_placeholder = thing, value_placeholder = value)
return my_xpath
look_for_v2("MyThing", "MyValue")
你缺少return語句在功能 –
好,只是認爲「漸無回」可能已經因爲 –