打印的Python ReportLab段落计数行

Question

有什么方法可以让我在reportlab中得到一个可流动段落的行数吗？ 我有一个很长的字符串，用不同的大小和字体打印。 我需要知道整个段落有多少行是用TA峈JUSTIFY对齐打印的。在

这能做到吗？在

下面是我的示例python文件

import os
import sys
import string
import pprint
import imp
import tempfile

from reportlab.pdfgen import canvas
from reportlab.platypus import Preformatted, XPreformatted, Paragraph, Frame, Image, \
     Table, TableStyle, Spacer
from reportlab.lib.enums import TA_LEFT, TA_RIGHT, TA_CENTER, TA_JUSTIFY
from reportlab.lib import styles
from reportlab.lib.styles import getSampleStyleSheet, ParagraphStyle
from reportlab.lib.pagesizes import *
from reportlab.lib import colors
import reportlab.rl_config
# Import as may be needed if we require embedded true type fonts
from reportlab.pdfbase import pdfmetrics
from reportlab.pdfbase.ttfonts import TTFont
from reportlab.lib.fonts import addMapping
from reportlab.graphics.barcode import code39, code128, code93
from reportlab.graphics.barcode import common
from reportlab.graphics.barcode import qr
from reportlab.graphics import renderPDF
from reportlab.graphics.shapes import Drawing
import string
import os
import imp
from reportlab.lib import colors


canv = canvas.Canvas('Output.pdf')


styles = getSampleStyleSheet()
parastyle = ParagraphStyle(name='Justify', alignment=TA_JUSTIFY)
parastyle.leading = 12
parastyle.fontSize = 11
styles.add(parastyle)

drawText = "The Avengers become divided, both over how to approach Loki and the revelation that S.H.I.E.L.D. plans to harness the Tesseract to develop weapons as a deterrent against hostile extraterrestrials. As the group argues, Barton and Loki's other possessed agents attack the Helicarrier, disabling one of its engines in flight and causing Banner to transform into the Hulk. Stark and Rogers work to restart the damaged engine, and Thor attempts to stop the Hulk's rampage. Romanoff reluctantly fights Barton, and knocks him unconscious, breaking Loki's mind control. Loki escapes after killing Coulson and ejecting Thor from the airship, while the Hulk falls to the ground after attacking a S.H.I.E.L.D. fighter jet. Fury uses Coulson's death to motivate the Avengers into working as a team. Stark and Rogers realize that for Loki, simply defeating them will not be enough; he needs to overpower them publicly to validate himself as ruler of Earth. Loki uses the Tesseract, in conjunction with a device Selvig built, to open a wormhole above Stark Tower to the Chitauri fleet in space, launching his invasion."

inch = INCH = 72
cm = CM = inch/2.54
mm = MM = cm/10


x=10*mm
y=240*mm
width=190*mm
height=10*mm

canv.saveState()
canv.translate(x,y)
canv.rotate(0)
canv.translate(-x,-y)

p = Paragraph(drawText, styles["Justify"])

p.wrapOn(canv, width, height)
p.drawOn(canv, x, y)

canv.showPage()
canv.save()

这是电流输出 Output

我需要知道段落中打印的行数。 在我的例子中，我必须得到11。在

如果我改变字体和字体大小，我必须得到相应的值。在

Answer 1

我只是偶然遇到了这个问题，同时也在寻找一些简单的方法来完成你的要求。不幸的是，我没有找到答案，所以我试着把它组合起来。虽然不漂亮，但很管用！在

我刚在你的后面加了这个代码可保存（）方法调用：

pixelRatio = 1.333333 # 1 point = 1.333333 pixels
# https://websemantics.uk/articles/font-size-conversion/
# http://www.endmemo.com/sconvert/pixelpoint.php#targetText=Pixel%E2%86%94Point%201%20Point,Twip%201%20Pixel%20%3D%2015%20Twip

fontLineHeight = styles["Justify"].fontSize * pixelRatio
boxWidth = width
boxHeight = height
boxLines = int(72/fontLineHeight)
boxLRBuffer = 0 # Adjust this to whatever inside margin/padding you have in your box
boxPixelCapacity = boxWidth * boxLines - boxLRBuffer # Total pixels in the box

# A list to hold the lines of text
textLines = []
# A pointer to indicate which character is being evaluated
position = len(drawText)
# Make a copy of the original string so as to not modify it
tempString = drawText
# This is a dummy string used to test the width of the string
testString1 = tempString
# Another dummy string to hold what is not being split into a line
# testString2 will be build going backwards from the last character
# to the character right after the line split
testString2 = ''
# Boolean flag to get out of the while loop
done = False
while not done:
    # Use pdfmetrics to get the line width in points based upon the fontName and fontSize used
    if pdfmetrics.stringWidth(testString1, styles["Justify"].fontName, styles["Justify"].fontSize, 'utf8') > boxWidth-boxLRBuffer*2:
        # Since the line is too long, move backwards through the string until an appropriate size is found
        # by decreasing the pointer position.  Spaces also take space.
        position -= 1
        if position >= 0:
            #since the the pointer has not reached the beginning of testString1
            testString1 = testString1[:position] # remove the last character from testString1
            testString2 = tempString[position:] # add the next character to testString2 for later use
    # Since testString1 now fits within the stringWidth
    # it must be checked to see if this is the last line
    # being processed.
    elif testString1 == testString2:
        # This must be the last line since it equals testString2
            textLines.append(testString2.strip())
            break
    # This is not the last line of text, so now work backwards in
    # the string to find a space so the line can be split
    elif ' ' in testString1:
        while testString1[position:] != ' ' and position >= 0:
            testString1 = testString1[:position]
            testString2 = tempString[position:]
            position -= 1
        if len(testString1):
            textLines.append(testString1.strip())
        else:
            textLines.append(testString2.strip())
            break
        tempString = tempString[position:].strip()
        testString1 = tempString
        position = len(tempString)
    elif testString1 == "":
        # It's done
        break
    else:
        # The text does not exceed the stringWidth
        textLines.append(testString1)
        # testString2 must be checked and if empty then it's done
        if testString2 == "":
            done = True
        else:
           tempString = tempString[position:].strip()
           testString1 = tempString
           position = len(tempString)
print(len(textLines))

我愿意接受建议，以使这段代码更好或更精简。在

Answer 2

我认为目前在Reportlab中根本不可能做到这一点，因为flowable不直接“知道”内容。另请参见this exchange on the reportlab mailing list。在