Python中使用循环语句打印三角形、菱形

前言：在学习开发语言循环语句的使用过程中，经常会打印各种形状来验证对循环语句的熟练掌握程度，接下来就使用python来打印多种形状练习。

如下示例中：变量i用于控制外层循环（图形行数），j用于控制空格的个数，k用于控制星号（*）的个数

#/usr/bin/python
rows = int(raw_input(‘please input a rows:‘))
i=j=k=1
if rows >= 3:
    for i in range(0,rows+1):
        for k in range(0,i):
           print ‘*‘,      # 注意这里的","，一定不能省略，可以起到不换行的作用
           k = k+1
        print ‘\n‘
    i = i+1
else:
    print (‘Please enter a number that greater than or equal to 3,thank you!‘)

1.2 打印空心等边三角形

#/usr/bin/python
rows = int(raw_input(‘please input a rows:‘))
for i in range(0,rows):
    for j in range(0,rows-i-1):
        print " ",
        j += 1
    for k in range(0,2*i+1):
        if k == 0 or k == 2*i:
            print "*",
        else:
            if i+1==rows and k%2==0:
                print "*",
            else:
                print " ",
        k += 1
    print "\n"
i += 1

#/usr/bin/python
rows = int(raw_input(‘please input a rows that rather than 2 :‘))
for i in range(0,rows):
    for j in range(0,rows-(i+1)):
        print " ",
        j += 1
    for k in range(0,(rows-1)*i+1):
        if k>=2*i+1 :
            print " ",
        else:
            print "*",
        k += 1
    print "\n"
i += 1

for i in range(0,rows-1):
    for j in range(0,i+1):
        print " ",
        j += 1
    for k in range(0,2*((rows-1)-i)-1):
        print "*",
        k += 1
    print "\n"
i += 1

2.2 打印空心菱形

# 打印空心菱形先打印上半部分rows行，在打印下半部分rows-1行

#/usr/bin/python
rows = int(raw_input(‘please input a rows:‘))
for i in range(0,rows):
    for j in range(0,rows-(i+1)):
        print " ",
        j += 1
    for k in range(0,(rows-1)*i+1):
        if k == 0 or k == 2*i:
            print "*",
        else:
            print " ",
        k += 1
    print "\n"
i += 1

for i in range(0,rows-1):
    for j in range(0,i+1):
        print " ",
        j += 1
    for k in range(0,2*((rows-1)-i)-1):
        if k == 0 or k==2*((rows-1)-i)-2:
            print "*",
        else:
            print " ",
        k += 1
    print "\n"
i += 1

# 网上也有些朋友先打印上半部分rows-1行，然后打印下半部分rows行

#/usr/bin/python
rows = int(raw_input(‘please input a rows:‘))
for i in range(0,rows):
    for j in range(0,rows-i):
        print " ",
        j += 1
    for k in range(0,2*i-1):
        if k == 0 or k == 2*i-2:
            print "*",
        else:
            print " ",
        k += 1
    print "\n"
i += 1

for i in range(0,rows):
    for j in range(0,i):
        print " ",
        j += 1
    for k in range(0,2*(rows-i)-1):
        if k == 0 or k == 2*(rows-i)-2:
            print "*",
        else:
            print " ",
        k += 1
    print "\n"
i += 1