Comparison of usage differences between%r and%s in Python

%r processing objects with the Rper () method

%s processing an object with the Str () method

The function str () is used to convert a value into a form suitable for human reading, while REPR () translates to a form for the interpreter to read (if there is no equivalent syntax, the SYNTAXERROR exception occurs) if an object does not have an explanatory form suitable for human reading, STR () returns a value equal to repr (). Many types, such as numerical or linked lists, dictionaries, have a uniform interpretation of each function.

In some cases, the result of both processing is the same, such as dealing with an int type object.

Example one:

Print "I am%d years old."% 22print "I am%s years old."% 22print "I am%r years old."% 22

return Result:

I am years old. I am years old. I am years old.

And in some cases, they're different.

Example two:

Text = "I am%d years old."% 22print "I said:%s."% textprint "I said:%r."% text

return Result:

I said:i am years old. I said: ' I am years old. '   #%r adds single quotation marks to strings

Look at one more situation

Example three:

Import datetimed = Datetime.date.today () print "%s"% dprint "%r"% d

return Result:

2017-08-16datetime.date (2017, 8, 16)

Visible,%r can reproduce the objects it represents (Rper () unambiguously recreate the object it represents) when printing