How to use substring in a string?

In Python, you can find the position of a substring using the find() and index() methods of a string, and extract the substring using slice operations.

1. search for a specific word or phrase within a larger text
2. a small section of a larger string

s = "Hello, World!"
index = s.find("World")
print(index)   # 输出: 7

1. find the position of a specific string within another string
2. locate
3. a portion of a string
4. Invalid value

s = "Hello, World!"
index = s.index("World")
print(index)   # 输出: 7

1. [from:start to finish]
2. Commence
3. finish
4. begin
5. The conclusion

s = "Hello, World!"
substring = s[7:12]
print(substring)   # 输出: World

1. The last element of the list.
2. second to last character

s = "Hello, World!"
substring = s[-6:-1]
print(substring)   # 输出: World

These techniques and procedures can assist you in locating and extracting substrings within a string.