Python For Everyone Chapter6 Exercises

Exercise 5: Take the following Python code that stores a string: str = ‘X-DSPAM-Confidence:0.8475’ Use find and string slicing to extract the portion of the string after the colon character and then use the float function to convert the extracted string into a floating point number.

解答：

str = 'X-DSPAM-Confidence:0.8475'
a = str.find('8')
c = str[a:]
print(c)

Exercise 6: Read the documentation of the string methods at https://docs.python.org/library/stdtypes.html#string-methods You might want to experiment with some of them to make sure you understand how they work. strip and replace are particularly useful.
The documentation uses a syntax that might be confusing. For example, in find(sub[, start[, end]]), the brackets indicate optional arguments.
So sub is required, but start is optional, and if you include start, then end is optional.