Python practice questions and answers

Remarks: Don't copy and paste to run directly, you need to type the code yourself to make progress, pay attention to line indentation

1. Output a number that is divisible by 2 within 100, and the result is to print 5 outputs per line

>>> n=0
>>> for i in range(100):
...     if i % 2 == 0:
...         print(i,end="  ")
...         n+=1
...         if n % 5 ==0:
...             print("\n")

2. Swap the values ​​of a and b

>>> a=1
>>> b=2
>>> a,b=b,a
>>> print(a,b)

3. The output -1 is true or false

>>> print(bool(-1))

4. Output 2 to the third power

print(2**3)

5. Square root of output 9

import math
print(math.sqrt(9))

6. Calculate the sum of ASCII encoding of az

count=0
for i in range(ord('a'),ord('z')+1):
    count=count+i
print(count)

7. The range of output range (10)

print(list(range(10)))

8. Output az reverse display

import string
print(string.ascii_lowercase[::-1])

9. Display the letters in the 2, 4, 6, 8, and 10 digits after a in az

for i in range(2,10,2):
    print(chr(ord('a')+i))

10. Count the number of a in the string

方法一：
s='abcdabcd'
print(s.count('a'))

方法二：用字典
>>> result={}
>>> for i in s:
...     if i in result.keys():
...         result[i]=result[i]+1
...     else:
...         result[i]=1
... print(result)

11. Remove a from a sentence

方法一：
>>> s="a boy,a girl. glory road is glory."
>>> result=""
>>> for i in s: #遍历字符串
...     if i!='a':  #不是a，就把字符串拼接到空的变量中
...         result+=i
... print("结果是：",result)

方法二：
s=s.replace('a', "")

12. Enter a number to compare the size with a randomly generated integer of 1-10

from pip._vendor.distlib.compat import raw_input
import random
a=int(raw_input("请输入你猜测的数字：\n"))
print("你猜测的数字是:",a)
b=random.randint(1,10)
print("随机数是:",b)
if a>b:
    print("猜大了, %s>%s" %(a,b))
elif a==b:
    print("猜对了, %s=%s" %(a,b))
else:
    print("猜小了, %s<%s" %(a,b))

13. Enter a number and compare it with a randomly generated integer from 1-10 until they are equal

from pip._vendor.distlib.compat import raw_input
import random
b=random.randint(1,10)
while 1:        #死循环
    a=int(raw_input("请输入你猜测的数字：\n"))
    print("你猜测的数字是:",a)
    if a > b:
        print("猜大了, %s>%s" %(a,b))
    elif a==b:
        print("猜对了, %s=%s" %(a,b))
        break
    else:
       print("猜小了, %s<%s" %(a,b))

14. Randomly output integers from 1 to 10 until it ends at 3

import random
a=1
while a!=3:
    a=random.randint(1,10)
    print(a)