Doris,2016.7.9+chapter7&8

=7.9 summer vacation HW=

1.for
for i in range(a,b)/list[a,b] Every iteration of i, i equal to next variable 2.while : Every integration of i, programmer must change the variable 3.while 1: if : break 4.tracint a program Being able to set a breakpoint where you need one is far more powerful. So we strongly encourage you to invest time in learning using to use your programming environment (PyScripter, in these notes) to full effect. print('...') 5.count digits code format="python" def num_zero_and_five_digits(n): count = 0 while n > 0: digit = n % 10 if digit == 0 or digit == 5: count = count + 1 n = n // 10 return count code

exercise
1. code format="python" n = 0 a = ［112,22,3,4,59,2］ for i in a:   if i % 2 == 1: n = n + 1 print (n) code 2. code format="python" a = ［1,3,4,2,5,6,7］ Sum = 0 for i in a : if i % 2 == 0: Sum = Sum + i print (Sum)

code 3. code format="python" a = ［-2,-4,25,-6,2］ Sum = 0 for i in a:   if i < 0 : Sum = Sum + i print (Sum)

code 4. code format="python" a = ［'asdfc','sdfi','sdfkj','d','asdas'］ count = 0 for i in a:   if len(i) == 5: count = count + 1 print(count)

code 5. code format="python" a = ［1,2,3,4,5,6,7,8,9］ Sum = 0 count = 0 for i in a : if i % 2 == 0: count = count + 1 if count != 1: Sum = Sum + i   else: Sum = Sum + i print(Sum) code 6. code a = ['aaa','bbb','ccc','sum','ccc'] n = 0 for i in a:   if i == 'sum': n = n + 1 break else: n = n + 1 print (n) code 8. code format="python" def print_mult_table(n): for i in range(1,n): for j in range(1,i+1): print(j,"*",i,"=",i*j,end=' ') print('  ') print_mult_table(10)

code 9. code format="python" def print_triangular_number(n): a=0 for i in range(1,n+1): a = a + i       print (i,'     ',a)

print_triangular_number(5) code 10. code format="python" def is_prime(n): if n < 2: return False else: for i in range(2,n): if n % i == 0: return True return False print(is_prime(19911121)) code 11. code format="python" import turtle a=[160,-43,270,-43] b=[20,10,8,12] n=0 for i in b:   n+=1 turtle.left(i) turtle.forward(a[n-1])

code 12. code format="python" import turtle import math

data=[(-100,100),(0,100),(-100,0),(0,0),(0,100),(-50,100+50/math.sin(45)),(-100,100),(-100,0),(0,0)]

scr=turtle.Screen alex=turtle.Turtle alex.pensize(5) alex.speed(0) alex.left(90)

for (i,j) in data: alex.goto(i,j)

scr.mainloop code 13. 2、5 14. code format="python" def num_digits(n): digit = 0 while 1: if -10 < n < 10: return digit+1 n = n // 10 digit=digit+1 print(num_digits(1000)) code 15. code format="python" def even_number_digit(n): digit = 0 while not -2 < n < 2: if n % 2 == 0 and n % 10 != 0: digit += 1 n = n // 10 return digit print(even_number_digit(1230)) code 16 code format="python" def sum_of_squares(xs): sum = 0 for i in xs: sum = sum + i**2 return sum

xs=[0] print(sum_of_squares(xs)) code 17. code format="python" def play_once(human_plays_first): """      Must play one round of the game. If the parameter       is True, the human gets to play first, else the       computer gets to play first.  When the round ends,       the return value of the function is one of       -1 (human wins),  0 (game drawn),   1 (computer wins).    """ # This is all dummy scaffolding code right at the moment...   import random                  # See Modules chapter ... rng = random.Random # Pick a random result between -1 and 1. result = rng.randrange(-1,2) print("Human plays first={0}, winner={1} "                       .format(human_plays_first, result)) return result def play_first(n): if n % 2 == 0: return True print('human first') else: return False print('computer first') def main: human=0 computer=0 drawn=0 while input('do you want to play again'=='yes'): result=play_once(play_first(n),human,drawn,computer) if result == 1: print ('you win !') human = human + 1 elif result == -1: print('coumpter win !') computer = computer + 1 else: print('game drawn!') drawn = drawn + 1 else: print('your score is',human,'the win rate is',human/(human+computer+drawn))
 * 1) Your friend will complete this function

code