python特定位置的字符串截取

1，index

img_path = "camel.png"
img_name = img_path[:-4]  # 通过索引截取camel

2，str.rfind(str, beg=0 end=len(string))

str = "this is really a string - example"
substr1 = "really"
substr2 = "_"

str[:str.rfind(substr1)]  # 截取this is

3，find() 是从字符串左边开始查询子字符串匹配到的第一个索引

rfind()是从字符串右边开始查询字符串匹配到的第一个索引