# [Python exercises]

2022-07-24 21:24:46lxw-pro

Personal Nickname ：lxw-pro
Personal perception ： “ Failure is the mother of success ”, This is the same truth , Sum up in failure , Grow in failure , To be IT A generation of masters in the world .

So-called ` If you want to learn programming well , Code problems are inevitable `, Come on , Get started with the code , Feel the mystery ！！！

## 1. Count the number of vowels in the string

Enter a string ending with a newline , Count and output the number of vowels in the string ( vowel :‘A’,‘E’,‘I’,‘O’,‘U’
,‘a’,‘e’,‘i’,‘o’,‘u’)

``````s = input().upper()
cs = 0
for i in s:
if i == '\n':
break
if 'A' in i or 'E' in i or 'I' in i or 'O' in i or 'U' in i:
cs += 1

print(cs)
``````

## 2. Generate 3 The power table of

Enter a non negative integer n, Generate one 3 The power table of , Output 3​0​​ ~3​n​​ Value . Power function calculation can be called 3 Power of .

``````import math

n = int(input())
for i in range(n+1):
print(f"pow(3, {
i}) = {
pow(3, i)}")
``````

## 3. Guess the number game

Two people participate in , One person input （ Set up ） A number , Guess the numbers alone , When the guesser enters a number , Prompt whether you guessed ：
If the guessed number is greater than the set number , Tips “ unfortunately , You guessed big ”; If the guessed number is less than the set number , Tips “ unfortunately , You guess it's small ”;
If the guessed number is equal to the set number , Tips “ Congratulations , Guess success ”; People who guess numbers guess at most 5 Time , If more times , Tips “ Guess number failed ”.

``````num = int(input(" Please enter the number you want to enter ："))
cs = 0
for i in range(1, 6):
guess = int(input(' Guess the number :'))
if i == 5:
print(" Guess number failed ！")
elif guess == num:
print(' Congratulations , Guess success ')
break
elif guess > num:
print(' unfortunately , Guess how big ~')
else:
print(' unfortunately , Guess it's small ~')

``````

## 4. Special 7

Output 100 within , All contain 7 or 7 The number of multiples of .

``````for i in range(1, 101):
if '7' in str(i) or i % 7 == 0:
print(i)
``````

## 5. Use for sentence , Realize printing 99 multiplication table

``````for i in range(1, 10):
for j in range(1, i+1):
print(f'{
j}*{
i}={
i*j}\t', end='')
print()
``````

## 6. Use only while sentence , Print digital pyramid

``````jc = int(input())
out = 1
while out <= jc:
inn = 1
while inn <= out:
print(inn, end=" ")
inn += 1
print()
out += 1
``````

## 7. Use while sentence , Realize printing 99 multiplication table

``````a = 1
while a < 10:
b = 1
while b <= a:
print("%d*%d=%d"%(b, a, a*b), end='\t')
b += 1
print()
a += 1
``````

## 8. Use list derivation , Realize printing 99 multiplication table ( Choose to do )

``````for n in range(10):
print(" ".join(["%d*%d=%-2d" % (m, n, m*n) for m in range(1, n+1)]))

``````

## 9. A mixture of for、while sentence , Realize printing 99 multiplication table

``````for k in range(1, 10):
w = 0
while w < k:
w += 1
print("{}*{}={}".format(w, k, k*w), end='\t')
print()
``````

## 10. Use python Realize the function of printing digital pyramid

``````num = int(input(" Please enter a number :"))
for i in range(0, num):
for j in range(num - i - 1, 0, -1):
print(' ', end=' ')
for k in range(-i, i + 1):
print(abs(k)+1, end=' ')
print()
``````

## 11. Use for sentence , Realize the function of printing 99 multiplication table

``````for i in range(1, 10):
for j in range(1, i+1):
print(f'{
j}*{
i}={
i*j}\t', end='')
print()
``````

## 12、 Create a function , To receive n Sum the numbers and enter

``````def s():
n = int(input(" Please enter a number "))
s = 0
for i in range(1, n+1):
s += i
print(s)

s()

``````

## 13、 Please use recursive function to find 10 The factorial

``````def jc(n):
if n == 0:
return 1
else:
return n*jc(n-1)

print(jc(10))
``````

Through function import, the randomly generated 10 Students' grades are judged and output .

``````import random

for i in range(1, 11):
n = random.randint(1, 101)
print(n)

if n >= 90:
print(' good ')
elif 80 <= n < 90:
print(" good ")
elif 70 <= n < 80:
print(" secondary ")
elif 60 <= n < 70:
print(" pass ")
else:
print(" fail, , There's work to be done ")
``````

## 15. Classic questions

python Programming to achieve the following functions ：

Yes 30 A man is trapped on a desert island , There is a ship , You can only install 15 people . So people lined up , The queue is their number . Number off , from 1 Start , Count to 9 People can't get on board . So circular , Until only 15 So far , Ask the number of people who can't get on board ？

``````peo = {
}
for x in range(1, 31):
peo[x] = 1
# print(peo)

i = 1
down = 0
hans = 0

while i <= 31:
if i == 31:
i = 1
elif down == 15:
break
else:
if peo[i] == 0:
i += 1
continue
else:
hans += 1
if hans == 9:
peo[i] = 0
hans = 0
print('{} No. can't go on board '.format(i), end=',')
down += 1
else:
i += 1
continue

``````

## Programming to achieve the following functions ：

1. Create two folders in the current directory ：test1、test2
2. stay test1 Under the folder , New text file a1.txt, And write content ：test a1
3. Copy test1 Under the a1.txt To test2 Under the folder , The file named a2.txt
4. open a2.txt file , Appending the content of writing ：write a2
``````import os
from shutil import copyfile

path1 = 'test1'
path2 = 'test2'
folder1 = os.path.exists(path1)
folder2 = os.path.exists(path2)
if not folder1:
os.makedirs(path1)
if not folder2:
os.makedirs(path2)
with open('test1/a1.txt', 'w') as f:
f.write('test a1')
copyfile('test1/a1.txt', 'test2/a2.txt')
with open('test2/a2.txt', 'a') as f:
f.write('write a2')
``````

————————————————————————————————————————————

# pandas Practice every day ：

`print() Just to change careers and see the results `

``````# -*- coding = utf-8 -*-
# @Time : 2022/7/19 14:45
# @Author : lxw_pro
# @File : pandas-2  practice .py
# @Software : PyCharm

import pandas as pd
import numpy as np

lxw2 = {"project": ['Python', 'Java', 'C', 'MySQL', 'Linux', 'Math', 'English', 'Python'],
"popularity": [91, 88, 142, 136, np.nan, 146, 143, 148]}

df = pd.DataFrame(lxw2)
``````

# 6. Fill in the average of the upper and lower values of the null value

``````df['popularity'] = df['popularity'].fillna(df['popularity'].interpolate())
print(df)

print()
``````

# 7. extract popularity The median value of the column is greater than 145 The line of

``````tq = df[df['popularity'] > 145]
print("popularity The column is greater than 145 Row has ：\n", tq)

print()
``````

# 8. according to project Column to remove duplicate values

``````qc = df.drop_duplicates(['project'])
print(" After removing duplicate values :\n", qc)

print()
``````

# 9. Calculation popularity Column average

``````avg = df['popularity'].mean()
print("popularity The average value of the column is ：{:.2f}".format(avg))

print()
``````

# 10. take project Column to list

``````lst = df['project'].to_list()
print("project Column to list by \n", lst)
``````

## The relevant operation results are as follows ：

6~8： 9~10： ### A word a day ：

A kind reminder , Don't turn the sense of urgency of ambition into the sense of panic of seizing the day , Everyone must get used to the reality of standing at the crossroads of life without traffic lights ！！

#### Ongoing update …

give the thumbs-up , Your recognition is my creation ` power `
Collection , Your favor is my effort ` Direction `
Comment on , Your opinion is my progress ` Wealth `
Focus on , Your love is my lasting ` insist ` 