Python的for..in循环写各种三角形和正方形

打印左下三角形

# 外层循环，控制行数
for i in range(1,6):
    # 内层循环，控制每行*的个数
    for j in range(1,i+1):
        # 因为print()自带一个\n，会默认换行，所以通过end=""，取消自动换行
        print("*",end = " ")
    # 每行执行完后换行
    print()

result:
* 
* * 
* * * 
* * * * 
* * * * * 

---

打印右上三角

for i in range(6):  
    for j in range(0,i):
        print(" ",end = " ")
    for k in range(i,6):
        print("*", end=" ")
    print()

result:
* * * * * * 
  * * * * * 
    * * * * 
      * * * 
        * * 
          * 

---

打印左上三角

for i in range(6):  
    for j in range(0,6 - i):
        print("*",end = " ")
    for k in range(6 - i,6):
        print(" ", end=" ")
    print()

result:
* * * * * * 
* * * * *   
* * * *     
* * *       
* *         
*

---

打印右下三角

for i in range(6):  
    for j in range(0,6 - i):
        print(" ",end = " ")
    for k in range(6 - i,6):
        print("*", end=" ")
    print()

result:
		  * 
        * * 
      * * * 
    * * * * 
  * * * * *

---

打印左下右上三角形

打印左下角三角形：for i in range(6):之后，range(0,i)
打印右上角三角形：在左下角的基础上，将"*“变成” "空格

for i in range(6):
    for j in range(0,i):
        print("*",end = " ")
    for k in range(i,6):
        print("-", end=" ")
    print()

result:
- - - - - - 
* - - - - - 
* * - - - - 
* * * - - - 
* * * * - - 
* * * * * - 

---

打印左上右下三角形

打印左上角三角形：for i in range(6):之后，range(0,6-i)
打印右下角三角形：在左上角的基础上，将"－“变成” "空格

for i in range(6):
    for j in range(0, 6 - i):
        print("*", end=" ")
    for k in range(6 - i, 6):
        print("-", end=" ")
    print()

result:
* * * * * * 
* * * * * - 
* * * * - - 
* * * - - - 
* * - - - - 
* - - - - - 

---

打印居中正三角

for i in range(6):
    for j in range(0, 6 - i):
        print(end=" ")
    for k in range(6 - i, 6):
        print("*", end=" ")
 print()

result:
     * 
    * * 
   * * * 
  * * * * 
 * * * * * 
* * * * * * 

---

打印正倒三角

for i in range(6):
    for j in range(0,i):
        print(end=" ")
    for j in range(i,6):
        print("*", end=" ")
print()

result:
 * * * * * 
  * * * * 
   * * * 
    * * 
     * 

---

实心正方形

for i in range(5):
    print("*  "*5)
print()

result:
*  *  *  *  *  
*  *  *  *  *  
*  *  *  *  *  
*  *  *  *  *  
*  *  *  *  * 

空心正方形

for i in range(4):
    if i == 0:
        print("*  " * 5)
    if i == 3:
        print("*  " * 5)
        continue
    for j in range(5):
        if j == 0:
            print("*  ",end=" ")
        if j == 4:
            print("*  ")
        else:
            print("  ",end="")

result:
*  *  *  *  *  
*           *  
*           *  
*           *  
*  *  *  *  *