Python函数的定义与调用方法实例

def name(arg1, arg2, ...,argN):
    statements

def repeator(s, n):
    result = s * n
    print(result)

def repeator(s, n):
    result = s * n
    print(result)
print(type(repeator))
# <class 'function'> 

def repeator(s, n):
    result = s * n
    print(result)
repeator('嗷', 3)
# 嗷嗷嗷

def name(arg1, arg2, ...,argN):
    statements 
    return value

def repeator(s, n):
    result = s * n
    print(result)
value = repeator('嗷', 3)
# 嗷嗷嗷
print(value)
# None

def repeator(s, n):
    result = s * n
    return result
print(repeator('嗷', 3))
# 嗷嗷嗷

def calculator(m, n): 
    return m+n, m-n, m*n, m/n
i, j = 2, 4
r1, r2, r3, r4 = calculator(i, j)
print(f'{i} 和 {j} 的加减乘除运算结果是：{r1}，{r2}，{r3}，{r4}')
# 2 和 4 的加减乘除运算结果是：6，-2，8，0.5

def avg(m, n):
    return (m + n) /2
print(avg(5, 2))
# 3.5

def priceChanger(p):
    p = p + 10 
    print('改变后的价格：{:.2f}'.format(p))
price = 10.8
priceChanger(price)
# 改变后的价格：20.80
print(price)
# 10.8

def contentChanger(name_list):
    name_list[0], name_list[1] = name_list[1], name_list[0]
    print('函数中的 name_list:', name_list)
language_name = ['C', 'Python']
contentChanger(language_name)
# 函数中的 name_list: ['Python', 'C']
print('调用函数后的 language_name:', language_name)
# 调用函数后的 language_name: ['Python', 'C']

def myMinus(num1, num2): 
    return num1 - num2
print(myMinus(5, 2))
# 3

def myMinus(num1, num2): 
    return num1 - num2
print(myMinus(2, 5))
# -3

def myMinus(num1, num2): 
    return num1 - num2
print(myMinus(num1=5, num2=2))
# 3
print(myMinus(num2=2, num1=5))
# 3

print(...)
    print(value, ..., sep=' ', end='\n', file=sys.stdout, flush=False)
    Prints the values to a stream, or to sys.stdout by default.
    Optional keyword arguments:
    file:  a file-like object (stream); defaults to the current sys.stdout.
    sep:   string inserted between values, default a space.
    end:   string appended after the last value, default a newline.
    flush: whether to forcibly flush the stream.

print('C', 'C++', 'Java', 'Python')
# C C++ Java Python

print('C', 'C++', 'Java', 'Python', sep='_')
# C_C++_Java_Python

def myMod(x, y=2): 
    return x % y
print(myMod(13,4))
# 1
print(myMod(13))
# 1

def m_value(*values):
    max_value = max(values)
    min_value = min(values)
    print(f'最大值: {max_value}, 最小值: {min_value}')
m_value(8, 6, 7, 4, 3, 9)
# 最大值: 9, 最小值: 3

def f(**info):
    if 'name' not in info.keys():
        print('必须拥有名称信息。')
    else:
        print(info['name'] + '的诞生年份：' + info.get('time', '不详'))
f(name = 'C', time = '1972')
# C的诞生年份：1972
f(name = 'Python')
# Python的诞生年份：不详

def f(name, time='不详'):
    if name and len(name) > 0:
        print(name + '的诞生年份：' + str(time))
    else:
        print('必须拥有名称信息。')
info1 = ['C', '1972']
f(*info1)
# C的诞生年份：1972
info2 = {'name': 'Python', 'time': '1989'}
f(**info2)
# Python的诞生年份：1989