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reportlab issue with line breaks using XPreformatted - additionall question mark printed

开发者 https://www.devze.com 2022-12-22 17:05 出处:网络
I\'m using XPreformatted to print some preformated text and I have an issue with the line breaks. The line breaks are correctly translated but additionaly I get a

I'm using XPreformatted to print some preformated text and I have an issue with the line breaks.

The line breaks are correctly translated but additionaly I get a "question mark" at the end of each 开发者_Go百科line.

This is my output:

first line?
second line?
some more text

I'm using django with mysql and the database field is a simple varchar field.

I checked it in the database and everything what is between the "e" and the "s" in "first linE Second line" is a new line character. With new line character I mean what is entered in the database when I press "enter" ;-)

Thus for me it seems strange that on the one hand the new line is correctly interpreted as a new line and additionally there is a wrong question mark.

hope to find some help here best regards tom


ok I know now how to circumvent this behavior. I just remove the character which is before the \n . Its the byte character 13. Thus I created a gready repair algorithm to remove this character and my pdf generating world is fine again ;-)

def repair_string_for_xpreformatted_use(value):
    #remove element before \n
    #it is an empty element interpreted from XPreformatted as a question mark
    #i guess this element is coming from the mysql db. test it with postgres db!
    #this is definitely a greedy repair algorithm

    lb_index = value.find('\n')
    start_index = 0
    end_index = len(value)
    value_rep = ""
    while lb_index != -1:
        lb_index = value.find('\n', 1)
        byte_list = toBytes(value[lb_index-1])
        if byte_list[0] == 13:
            #13 is the strange byte character which should not be there. remove it.. bye bye number 13
            value_rep += value[start_index:lb_index-1]
        else:
            #do not remove the character. we do not want to strip some user information ;-)
            value_rep += value[start_index:lb_index]

        value = value[lb_index:end_index]
        if lb_index == (end_index -1) or lb_index == end_index:
            lb_index = -1
        end_index = len(value)
    return value_rep

How to use it:

from reportlab.platypus import XPreformatted
footerstyle = ParagraphStyle(name='footerstyle', leading=6, spaceBefore=0, spaceAfter=0, textColor=gray2, fontName='Calibri', fontSize=5, alignment=TA_RIGHT)
footer_text_rep = repair_string_for_xpreformatted_use(footer_text)
footer_text_pre = XPreformatted(smart_str(footer_text_rep), footerstyle)
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