Python String | index method
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Python's String.index(~) method returns the index of the first occurrence of the specified substring in the source string. If the substring is not found, ValueError exception is raised.
Parameters
1. sub | string
The substring.
2. start | string | optional
The index of the source string from which to consider (inclusive).
3. end | string | optional
The index of the source string at which to halt the method (exclusive).
Return Types
If substring is found, then the index of the first character of the substring is returned.
If not found, then ValueError exception is raised.
Examples
Basic usage
To obtain the starting index of the first occurrence of "bc":
x = "abcdbc"x.index("bc")
1
When a substring is not found, ValueError is raised:
x = "abcdbc"x.index("gg")
ValueError: substring not found
Specifying start parameter
To start searching from index 2 (inclusive):
x = "abcdbc"x.index("bc", 2)
4
Specifying end parameter
To stop searching at index 3 (exclusive):
x = "abcdbc"x.index("cd", 3)
ValueError: substring not found
