调整reportlab.platypus.Paragraph的大小是否可流动？

Question

我得到了以下代码，试图调整reportlab鸭嘴兽flowable文本的字体大小，直到它适合我给定的可用高度。但是我发现flowable段并没有在递归的每个循环中保存它的style.fontSize属性，python的baulks具有无限递归。

def fits_space(w,h,aW,aH,p):
    """
    Determines if inputted text fits in the space given for a paragraph
    and if it doesn't, reduces the font-size until it does.

    """
    if w<=aW and h<=aH:
        # return font size to apply it to the para again
        print "final font_size: %d" % p.style.fontSize
        return p # now render the paragraph in the doctemplate
    else: 
        p.style.fontSize -= 1
        w,h = p.wrap(aW, aH)
        fits_space(w,h,aW,aH,p)

def renderPage(name, text):
    doc = SimpleDocTemplate("%s.pdf" % name)
    parts = []
    style = ParagraphStyle(name='fancy')
    style.fontSize = 150
    p = Paragraph(text, style)
    aW = PAGE_WIDTH-4*inch  # available width and height 
    aH = PAGE_HEIGHT-4*inch 
    w,h = p.wrap(aW, aH) # find required space
    p = fits_space(w,h,aW,aH,p) # recursively fit the font size to the text
    parts.append(p)
    doc.build(parts)

有人能告诉我为什么-在fits_space（）函数中，在else子句中，当我调用p.wrap（aW，aH）时，输出的值与我将段落的字体大小减小1之前的值相同吗？如果我减小字体大小的话，包装的高度肯定要小一些？

你知道我错在哪里吗？

更新 Nitzie在下面的代码几乎可以工作只需要在样式中添加一个resizer。在我的例子中也是leading：

def shrink_font_size(aW, aH, text, style):
    """Shrinks font size by using pdfmetrics to calculate the height
    of a paragraph, given the font name, size, and available width."""
    def break_lines(text, aW):
        # simpleSplit calculates how reportlab will break up the lines for
        # display in a paragraph, by using width/fontsize.
        return simpleSplit(text, style.fontName, style.fontSize, aW)

    def line_wrap(lines, style):
        # Get overall width of text by getting stringWidth of longest line
        width = stringWidth(max(lines), style.fontName, style.fontSize)
        # Paragraph height can be calculated via line spacing and number of lines.
        height = style.leading * len(lines)
        return width, height

    lines = break_lines(text, aW)
    width, height = line_wrap(lines, style)

    while height > aH or width > aW:
        style.fontSize -= 1
        style.leading -= 1 # do this if you're leading is based on the fontSize
        lines = break_lines(text, aW)
        width, height = line_wrap(lines, style)

短暂性脑缺血发作