任务一
print(sum) sum=42 print(sum) def inc(n): sum=n+1 print(sum) return sum sum=inc(7) +inc(7) print(sum)
不同,sum1:内置函数,2:变量名,3:定义新函数,4:函数值
任务二
def func1(a, b, c, d, e, f): '''返回参数a,b,c,d,e,f构成的列表默认,参数按位置传递; 也支持关键字传递 ''' return [a,b,c,d,e,f] def func2(a, b, c,*, d, e, f): '''返回参数a,b,c,d,e,f构成的列表 *后面的参数只能按关键字传递 ''' return [a,b,c,d,e,f] def func3(a, b, c, /, d, e, f): '''返回参数a,b,c,d,e,f构成的列表 /前面的参数只能按位置传递 ''' return [a,b,c,d,e,f] # func1调用:按位置传递、按参数传递都可以 print( func1(1,9,2,0,5,3) ) print( func1(a=1, b=9, c=2, d=0, e=5, f=3) ) print( func1(1,9,2, f=3, d=0, e=5)) # func2调用:d,e,f必须按关键字传递 print( func2(11, 99, 22, d=0, e=55, f=33) ) print( func2(a=11, b=99, c=22, d=0, e=55, f=33) ) # func3调用:a,b,c必须按位置传递 print( func3(111, 999, 222, 0, 555, 333)) print( func3(111, 999, 222, d=0, e=555, f=333) ) list1= [1, 9, 8, 4] print( sorted(list1) ) print( sorted(list1, reverse=True) ) print( sorted(list1) )
python内置函数sorted()中,参数reverse的传递方式是否必须使用关键字传递?
不一定必须使用关键字传递。
def func(a, b, c, /, *, d, e, f): return( [a,b,c,d,e,f] ) # 补足一行代码,调用func()并打印生成的列表,使得结果为[1,2,3,4,5,6] print(func1(a=1, b=2, c=3, d=4, e=5, f=6))
任务三
def solve(a, b, c): ''' 求解一元二次方程, 返回方程的两个根 :para: a,b,c: int 方程系数 :return: tuple ''' delta = b*b - 4*a*c delta_sqrt = abs(delta)**0.5 p1 = -b/2/a; p2 = delta_sqrt/2/a if delta>=0: root1 = p1 + p2 root2 = p1 - p2 else: root1 = complex(p1, p2) root2 = complex(p1, -p2) return root1, root2 print(solve.__doc__) while True: try: a,b,c = eval(input('Enter eqution coefficient: ')) if a == 0: raise except: print('invalid input, or, a is zero') break else: root1, root2 = solve(a, b, c) print(f'root1 = {root1:.2f}, root2 = {root2:.2f}') print()
观察函数solve()的说明信息,打印出来了。
任务四
def list_generator(begin,end,step=1): list=[] while begin<=end: list.append(begin) begin=begin+step return list list1 = list_generator(-5, 5) print(list1) list2 = list_generator(-5, 5, 2) print(list2) list3 = list_generator(1, 5, 0.5) print(list3)
任务六
def encoder(n): list1 = [] for i in n: x = ord(i) if 65 <= x <= 90 or 97 <= x <= 122: if 65 <= x + 5 <= 90 or 97 <= x + 5 <= 122: y = chr(x + 5) list1.append(y) else: y = chr(x - 21) list1.append(y) else: list1.append(i) z = "".join(list1) return z def decoder(n): list1 = [] for i in n: x = ord(i) if 65 <= x <= 90 or 97 <= x <= 122: if 65 <= x - 5 <= 90 or 97 <= x - 5 <= 122: y = chr(x - 5) list1.append(y) else: y=chr(90-(65-(x-5))+1) list1.append(y) else: list1.append(i) z = "".join(list1) return z n = input('输入英文文本:') x1 = encoder(n) x2 = decoder(x1) print(f'编码后的文本:{x1}') print(f'解码后的文本:{x2}')