str is the class of strings. Calling str creates a string. The documentation calls this a "function" because it looks like one. Similarly for ... ... <看更多>

Therefore, you cannot use a string variable len as a function anymore. ... you might only restart your kernel of python. ... <看更多>

Use built-in functions to convert between integers, floating point numbers, and strings. ... Character string (usually called “string”, str ): text. ... <看更多>