Python's position parameter, the difference between the default parameters, keyword parameters, variable parameter
1. Location parameter
- The parameters required to define the position of the reference transfer function is called
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DEF print_hello (name, Sex): Print ( ' the Hello% S% S, is available for purchase to Python world! ' % (name, ' Mr. ' )) print_hello ( ' Nick ' , ' sir ' ) # Output: Mr. hello Nick, welcome to python world!
Location parameters must be in strict accordance with the order parameter passing
2. Keyword parameters
- In the function call, the "key-on" form as a function parameter, not in accordance with the parameters passed to the function position
- note:
- → key parameters must be in the right position parameters
- For the same parameter value can not be repeated passages
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# In order as a function of the parameter passed by value DEF MSG (name, Age, Sex): Print ( " the Hello, your name IS% S, Age IS% S, Sex IS% S " % (name, Age, Sex)) MSG ( ' Nick ' , 23 is, ' MALE ' ) # outputs: the Hello, Nick your name IS, IS 23 is Age, Sex MALE IS # when positional parameters and keyword parameters, the position of the keyword parameter argument following MSG ( ' Tony ' , 12 is, Sex = ' MALE ' ) # parameter multiple keywords parameters, regardless of the order parameter keyword MSG (Sex = ' FEMALE ' , name = ' Amy', age=56)
3. Default parameters
- When defining the function, you can provide default values for shape parameters. For parameter has a default value, if the function is called, the value for the parameter passed in by value, otherwise the default value
- note:
- When calling the function may not have to pass the parameter value defaults
- Whether defined functions or calls, default parameters should be defined formal parameters in the right position
- Only once when defining assignment
- Default parameters should generally be defined as immutable type