Python tkinter将canvas保存为postscript并添加到pdf

Question

我有一个简单的python tkinter绘图程序(用户使用鼠标在画布上绘制).我的目标是保存最终的绘图并将其放入带有其他内容的pdf文件中.

环顾四周后,我意识到我只能将画布绘图保存为这样的postscript文件

canvas.postscript(file="file_name.ps", colormode='color')

所以,我想知道是否有任何方式(任何python模块？)将允许我将postscript文件作为图像插入pdf文件.

可能吗？

Answer 1

正如在这个答案中提到的,一个可能的解决方法是打开一个子进程来使用ghostscript:

canvas.postscript(file="tmp.ps", colormode='color')
process = subprocess.Popen(["ps2pdf", "tmp.ps", "result.pdf"], shell=True)

另一种解决方案是使用ReportLab,但由于它addPostScriptCommand不是非常可靠,我认为你必须首先使用Python Imaging Library将PS文件转换为图像,然后将其添加到ReportLab Canvas中.但是,我建议使用ghostscript方法.

这是我用来看它是否有效的基本概念证明:

"""
Setup for Ghostscript 9.07:

Download it from http://www.ghostscript.com/GPL_Ghostscript_9.07.html
and add `/path/to/gs9.07/bin/` and `/path/to/gs9.07/lib/` to your path.
"""

import Tkinter as tk
import subprocess
import os

class App(tk.Tk):
    def __init__(self):
        tk.Tk.__init__(self)
        self.title("Canvas2PDF")
        self.line_start = None
        self.canvas = tk.Canvas(self, width=300, height=300, bg="white")
        self.canvas.bind("<Button-1>", lambda e: self.draw(e.x, e.y))
        self.button = tk.Button(self, text="Generate PDF",
                                command=self.generate_pdf)
        self.canvas.pack()
        self.button.pack(pady=10)

    def draw(self, x, y):
        if self.line_start:
            x_origin, y_origin = self.line_start
            self.canvas.create_line(x_origin, y_origin, x, y)
            self.line_start = None
        else:
            self.line_start = (x, y)

    def generate_pdf(self):
        self.canvas.postscript(file="tmp.ps", colormode='color')
        process = subprocess.Popen(["ps2pdf", "tmp.ps", "result.pdf"], shell=True)
        process.wait()
        os.remove("tmp.ps")
        self.destroy()

app = App()
app.mainloop()