Detailed explanation of the difference between *args and **kwargs in Python programming

I believe that the friends who learn Python must have such an embarrassing situation that giving a function will not be used.

The reason is: I don't know what the types in the parameter list mean, for example, beginners will wonder: how to use *args and **kwargs.

When you know this, I guess you will be able to use many functions!

Usage of # * args: When the number of parameters passed in is unknown and the parameter name is not needed.

def func_arg(farg, *args):
    print("formal arg:", farg)
    for arg in args:
        print("another arg:", arg)
func_arg(1,"youzan",'dba','4 Block 5 The girl ')
print("-----------------------")

# The output is as follows:

#formal arg: 1
# another arg: youzan
# another arg: dba
# another arg: A girl for 4.50 yuan
# -----------------------

Usage of # **kwargs: When the number of parameters passed in is unknown, but the name of the parameter needs to be known (immediately think of dictionary, that is, key-value pair)

def func_kwargs(farg, **kwargs):
    print("formal arg:", farg)
    for key in kwargs:
        print("keyword arg: %s: %s" % (key, kwargs[key]))
func_kwargs(1 ,id=1, name='youzan', city='hangzhou',age ='20',4 Block 5 The girl is  = ' There is a long way to go ')
print('--------------------')

# The output is as follows:

# formal arg: 1
# keyword arg: id: 1
# keyword arg: name: youzan
# keyword arg: city: hangzhou
# keyword arg: age: 20
# keyword arg: The girl with 4.50 is: There is a long way to go

Use it to convert parameters to dictionaries

def kw_dict(**kwargs):
    return kwargs
print(kw_dict(a=1,b=2,c=3))

The output is as follows:

# --------------------

# {'a': 1, 'b': 2, 'c': 3}

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