Python - =字符串中的空格

Question

我试图从for循环内的字符串中删除一个空格.我能够让它为添加空间而工作,但删除不起作用.

这是我的代码:

letterHeight = 10

def nLetter():
    x = 0
    diagonal = ""
    vertical = "          "
    while x < letterHeight:
        print "*"+diagonal+"*"+vertical+"*"
        diagonal += " "
        vertical -= " "
        x += 1

nLetter()

错误: TypeError: unsupported operand type(s) for -=: 'str' and 'str'

Answer 1

字符串不支持减法; 应删除哪一个空格？改为使用切片:

vertical = vertical[:-1]

这将通过从除最后一个字符之外的所有字符创建新字符串来删除最后一个字符:

>>> "abcd"[:-1]
'abc'