128 lines
3.7 KiB
Python
128 lines
3.7 KiB
Python
"""Basic regular expression demostration facility.
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This displays a window with two type-in boxes. In the top box, you enter a
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regular expression. In the bottom box, you enter a string. The first
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match in the string of the regular expression is highlighted with a yellow
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background (or red if the match is empty -- then the character at the match
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is highlighted). The highlighting is continuously updated. At the bottom
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are a number of checkboxes which control the regular expression syntax used
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(see the regex_syntax module for descriptions). When there's no match, or
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when the regular expression is syntactically incorrect, an error message is
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displayed.
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"""
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from Tkinter import *
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import regex
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import regex_syntax
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class RegexDemo:
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def __init__(self, master):
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self.master = master
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self.topframe = Frame(self.master)
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self.topframe.pack(fill=X)
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self.promptdisplay = Label(self.topframe, text="Enter a string:")
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self.promptdisplay.pack(side=LEFT)
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self.statusdisplay = Label(self.topframe, text="", anchor=W)
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self.statusdisplay.pack(side=LEFT, fill=X)
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self.regexdisplay = Entry(self.master)
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self.regexdisplay.pack(fill=X)
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self.regexdisplay.focus_set()
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self.labeldisplay = Label(self.master, anchor=W,
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text="Enter a string:")
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self.labeldisplay.pack(fill=X)
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self.labeldisplay.pack(fill=X)
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self.stringdisplay = Text(self.master, width=60, height=4)
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self.stringdisplay.pack(fill=BOTH, expand=1)
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self.stringdisplay.tag_configure("hit", background="yellow")
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self.addoptions()
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self.regexdisplay.bind('<Key>', self.recompile)
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self.stringdisplay.bind('<Key>', self.reevaluate)
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self.compiled = None
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self.recompile()
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btags = self.regexdisplay.bindtags()
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self.regexdisplay.bindtags(btags[1:] + btags[:1])
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btags = self.stringdisplay.bindtags()
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self.stringdisplay.bindtags(btags[1:] + btags[:1])
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def addoptions(self):
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self.frames = []
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self.boxes = []
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self.vars = []
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for name in ( 'RE_NO_BK_PARENS',
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'RE_NO_BK_VBAR',
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'RE_BK_PLUS_QM',
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'RE_TIGHT_VBAR',
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'RE_NEWLINE_OR',
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'RE_CONTEXT_INDEP_OPS'):
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if len(self.boxes) % 3 == 0:
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frame = Frame(self.master)
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frame.pack(fill=X)
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self.frames.append(frame)
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val = getattr(regex_syntax, name)
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var = IntVar()
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box = Checkbutton(frame,
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variable=var, text=name,
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offvalue=0, onvalue=val,
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command=self.newsyntax)
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box.pack(side=LEFT)
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self.boxes.append(box)
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self.vars.append(var)
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def newsyntax(self):
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syntax = 0
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for var in self.vars:
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syntax = syntax | var.get()
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regex.set_syntax(syntax)
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self.recompile()
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def recompile(self, event=None):
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try:
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self.compiled = regex.compile(self.regexdisplay.get())
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self.statusdisplay.config(text="")
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except regex.error, msg:
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self.compiled = None
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self.statusdisplay.config(text="regex.error: %s" % str(msg))
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self.reevaluate()
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def reevaluate(self, event=None):
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try:
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self.stringdisplay.tag_remove("hit", "1.0", END)
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except TclError:
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pass
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if not self.compiled:
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return
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text = self.stringdisplay.get("1.0", END)
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i = self.compiled.search(text)
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if i < 0:
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self.statusdisplay.config(text="(no match)")
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else:
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self.statusdisplay.config(text="")
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regs = self.compiled.regs
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first, last = regs[0]
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if last == first:
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last = first+1
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self.stringdisplay.tag_configure("hit",
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background="red")
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else:
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self.stringdisplay.tag_configure("hit",
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background="yellow")
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pfirst = "1.0 + %d chars" % first
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plast = "1.0 + %d chars" % last
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self.stringdisplay.tag_add("hit", pfirst, plast)
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self.stringdisplay.yview_pickplace(pfirst)
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# Main function, run when invoked as a stand-alone Python program.
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def main():
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root = Tk()
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demo = RegexDemo(root)
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root.protocol('WM_DELETE_WINDOW', root.quit)
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root.mainloop()
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if __name__ == '__main__':
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main()
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