# 条件并不是必须得时布尔值，这里的条件会进行隐式的数据类型转换，哪怕是数字 字符串也可以进行判断。
if 条件:
    条件为True执行的语句
else:
    条件为False执行的语句
if 条件:
    条件为True执行的语句

if 条件1:
    条件1为True执行的语句
elif 条件2:
    条件2为True执行的语句
elif 条件n:
    条件n为True执行的语句
else:
    都不符合条件时执行的语句

match subject:
    case <pattern_1>:
        <action_1>
    case <pattern_2>:
        <action_2>
    case <pattern_3>:
        <action_3>
    case _:
        <action_wildcard>

day = 4
match day:
  case 0:
    print('周日')
  case 1:
    print('周一')
  case 2:
    print('周二')
  case 3:
    print('周三')
  case 4:
    print("周四")
  case 5:
    print('周五')
  case 6:
    print('周六')
  case _:
    print("输入错误")

import datetime
import calendar

today = datetime.datetime.now().weekday()
# 获取到今天是周几的英文单词
day = calendar.day_name[today]

match day:
  case "Monday":
    print('周一')
  case "Tuesday":
    print('周二')
  case "Wednesday":
    print('周三')
  case "Thursday":
    print('周四')
  case "Friday":
    print('周五')
  case "Saturday":
    print('周六')
  case "Sunday":
    print('周日')
  case _:
    print("输入错误")

import datetime
today = datetime.datetime.now().weekday() # 获取到今天是周几用 0 - 6表示 python中默认0代表周一
print(today) # 0 - 6
match today:
  case 6:
    print('周日')
  case 0:
    print('周一')
  case 1:
    print('周二')
  case 2:
    print('周三')
  case 3:
    print("周四")
  case 4:
    print('周五')
  case 5:
    print('周六')
  case _:
    print("输入错误")

range(10) # [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
range(5, 7) # [5, 6]
range(5, 10) # [5, 6, 7, 8, 9]

for i in range(参数): # i就是对应的range中的每个值
    代码
else:
    # 循环结束后执行else

for i in range(1, 101):
  if i % 3 == 0 and i % 5 == 0:
    print(i)

i = 1
for j in range(1, 10):
  print(i, j)

i2 = 2
for j in range(1, 10):
  print(i2, j)

for i in range(1, 10):
  for j in range(1, 10):
    print(i, j)

#-----------------
for i in range(1, 10):
  for j in range(1, 10):
    # print(str(i) + "x" + str(j) + '=' + str(i * j))
    print("{}x{}={}".format(j, i, i * j), end="\t")
  print()

#-------------------
for i in range(1, 10):
  for j in range(1, i + 1):
    # print(str(i) + "x" + str(j) + '=' + str(i * j))
    print("{}x{}={}".format(j, i, i * j), end="\t")
  print()

# 什么是质数
# 想要判断一个数是不是质数，就要拿这个数和 2 - (数 -1）的所有数字进行比较
# 比如要判断10 (2 3 4 5 6 7 8 9)
# 判断2 - 100有多少个质数
for i in range(2, 101):
  # print("判断的数字是{}".format(i))
  for j in range(2, i):
    # print("{}是否能被{}整除".format(i, j), i % j == 0)
    if i % j == 0: # 如果判断过程中有一个能被某个数字整除则直接break
      break # 结束该循环 下面代码不再执行
    # 如果j是最后一个数 i - 1并且没有被break 说明这个数是质数
    if j == i - 1:
      print(i)
      
 # AI 
 # 100以内的质数
for i in range(2, 101):
  for j in range(2, i):
    if i % j == 0:
      break
  else:
    print(i)

# ⭐⭐⭐⭐⭐ 
# ⭐⭐⭐⭐⭐
# ⭐⭐⭐⭐⭐
# ⭐⭐⭐⭐⭐
# ⭐⭐⭐⭐⭐

for i in range(5):
  for j in range(5):
    print('⭐', end="")
  print()

print("\n")

# ⭐
# ⭐⭐
# ⭐⭐⭐
# ⭐⭐⭐⭐
# ⭐⭐⭐⭐⭐

for i in range(5):
  for j in range(0, i + 1):
    print('⭐', end="")
  print()

print()

# ⭐⭐⭐⭐⭐  0 1 2 3 4 range(0, 5)
# ⭐⭐⭐⭐     1 2 3 4 range(1, 5)
# ⭐⭐⭐        2 3 4 range(2, 5)
# ⭐⭐           3 4 range(3, 5)
# ⭐              4 range(4, 5)

for i in range(5):
  for j in range(i, 5):
    print('⭐', end="")
  print()
  
  
print()
#     ⭐ 4空1星
#    ⭐⭐ 3空2星
#   ⭐⭐⭐ 2空3星
#  ⭐⭐⭐⭐ 1空4星
# ⭐⭐⭐⭐⭐ 0空5星

for i in range(5):
  num = 4 - i
  for j in range(5):
    # 在j < num 时输出空格 j >= 输出 星
    if j < num:
      print(' ', end="")
    else:
      print('⭐', end="")
  print()

i = 0
while i < 10:
    执行的代码
    i += 1
else:
    # 条件不满足的执行else (循环结束后)

# while 循环 0 - 5
i = 0
while i < 5: # 不包含5
  print(i)
  i += 1

# while循环 3 - 10
i = 3
while i < 10: # 不包含10
  print(i)
  i += 1

# whil 循环 10 - 3
i = 10
while i > 3:
  print(i)
  i -= 1

i = 0
while i < 5:
  # 再来一个循环生成j
  j = 0
  while j < 5:
    print('⭐', end="")
    j += 1
  print()
  i += 1

for i in range(5):
  for j in range(5):
    print('⭐', end="")
  print()

for i in range(10):
    if i == 5:
        break
    print(i) # 0 1 2 3 4 

for i in range(10):
    if i == 5:
        continue 
    print(i) # 0 1 2 3 4 6 7 8 9