New demo -- Perl style regular expression matching.
Slightly more featureful than regexdemo.py.
diff --git a/Demo/tkinter/guido/redemo.py b/Demo/tkinter/guido/redemo.py
new file mode 100644
index 0000000..1502b9d
--- /dev/null
+++ b/Demo/tkinter/guido/redemo.py
@@ -0,0 +1,183 @@
+"""Basic regular expression demostration facility (Perl style syntax).
+
+This displays a window with two type-in boxes. In the top box, you
+enter a Perl style regular expression. In the bottom box, you enter a
+string. The first match in the string of the regular expression is
+highlighted with a yellow background (or red if the match is empty --
+then the character at the match is highlighted). The highlighting is
+continuously updated. At the bottom are a number of checkboxes which
+control the regular expression options used (see the re module for
+descriptions). When there's no match, or when the regular expression
+is syntactically incorrect, an error message is displayed.
+
+"""
+
+from Tkinter import *
+import re
+
+class ReDemo:
+
+ def __init__(self, master):
+ self.master = master
+
+ self.promptdisplay = Label(self.master, anchor=W,
+ text="Enter a Perl-style regular expression:")
+ self.promptdisplay.pack(side=TOP, fill=X)
+
+ self.regexdisplay = Entry(self.master)
+ self.regexdisplay.pack(fill=X)
+ self.regexdisplay.focus_set()
+
+ self.addoptions()
+
+ self.statusdisplay = Label(self.master, text="", anchor=W)
+ self.statusdisplay.pack(side=TOP, fill=X)
+
+ self.labeldisplay = Label(self.master, anchor=W,
+ text="Enter a string to search:")
+ self.labeldisplay.pack(fill=X)
+ self.labeldisplay.pack(fill=X)
+
+ self.showframe = Frame(master)
+ self.showframe.pack(fill=X, anchor=W)
+
+ self.showvar = StringVar(master)
+ self.showvar.set("first")
+
+ self.showfirstradio = Radiobutton(self.showframe,
+ text="Highlight first match",
+ variable=self.showvar,
+ value="first",
+ command=self.recompile)
+ self.showfirstradio.pack(side=LEFT)
+
+ self.showallradio = Radiobutton(self.showframe,
+ text="Highlight all matches",
+ variable=self.showvar,
+ value="all",
+ command=self.recompile)
+ self.showallradio.pack(side=LEFT)
+
+ self.stringdisplay = Text(self.master, width=60, height=4)
+ self.stringdisplay.pack(fill=BOTH, expand=1)
+ self.stringdisplay.tag_configure("hit", background="yellow")
+
+ self.grouplabel = Label(self.master, text="Groups:", anchor=W)
+ self.grouplabel.pack(fill=X)
+
+ self.grouplist = Listbox(self.master)
+ self.grouplist.pack(expand=1, fill=BOTH)
+
+ self.regexdisplay.bind('<Key>', self.recompile)
+ self.stringdisplay.bind('<Key>', self.reevaluate)
+
+ self.compiled = None
+ self.recompile()
+
+ btags = self.regexdisplay.bindtags()
+ self.regexdisplay.bindtags(btags[1:] + btags[:1])
+
+ btags = self.stringdisplay.bindtags()
+ self.stringdisplay.bindtags(btags[1:] + btags[:1])
+
+ def addoptions(self):
+ self.frames = []
+ self.boxes = []
+ self.vars = []
+ for name in ('IGNORECASE',
+ 'LOCALE',
+ 'MULTILINE',
+ 'DOTALL',
+ 'VERBOSE'):
+ if len(self.boxes) % 3 == 0:
+ frame = Frame(self.master)
+ frame.pack(fill=X)
+ self.frames.append(frame)
+ val = getattr(re, name)
+ var = IntVar()
+ box = Checkbutton(frame,
+ variable=var, text=name,
+ offvalue=0, onvalue=val,
+ command=self.recompile)
+ box.pack(side=LEFT)
+ self.boxes.append(box)
+ self.vars.append(var)
+
+ def getflags(self):
+ flags = 0
+ for var in self.vars:
+ flags = flags | var.get()
+ flags = flags
+ return flags
+
+ def recompile(self, event=None):
+ try:
+ self.compiled = re.compile(self.regexdisplay.get(),
+ self.getflags())
+ bg = self.promptdisplay['background']
+ self.statusdisplay.config(text="", background=bg)
+ except re.error, msg:
+ self.compiled = None
+ self.statusdisplay.config(
+ text="re.error: %s" % str(msg),
+ background="red")
+ self.reevaluate()
+
+ def reevaluate(self, event=None):
+ try:
+ self.stringdisplay.tag_remove("hit", "1.0", END)
+ except TclError:
+ pass
+ try:
+ self.stringdisplay.tag_remove("hit0", "1.0", END)
+ except TclError:
+ pass
+ self.grouplist.delete(0, END)
+ if not self.compiled:
+ return
+ self.stringdisplay.tag_configure("hit", background="yellow")
+ self.stringdisplay.tag_configure("hit0", background="orange")
+ text = self.stringdisplay.get("1.0", END)
+ last = 0
+ nmatches = 0
+ while last <= len(text):
+ m = self.compiled.search(text, last)
+ if m is None:
+ break
+ first, last = m.span()
+ if last == first:
+ last = first+1
+ tag = "hit0"
+ else:
+ tag = "hit"
+ pfirst = "1.0 + %d chars" % first
+ plast = "1.0 + %d chars" % last
+ self.stringdisplay.tag_add(tag, pfirst, plast)
+ if nmatches == 0:
+ self.stringdisplay.yview_pickplace(pfirst)
+ groups = list(m.groups())
+ groups.insert(0, m.group())
+ for i in range(len(groups)):
+ g = "%2d: %s" % (i, `groups[i]`)
+ self.grouplist.insert(END, g)
+ nmatches = nmatches + 1
+ if self.showvar.get() == "first":
+ break
+
+ if nmatches == 0:
+ self.statusdisplay.config(text="(no match)",
+ background="yellow")
+ else:
+ self.statusdisplay.config(text="")
+
+
+# Main function, run when invoked as a stand-alone Python program.
+
+def main():
+ root = Tk()
+ demo = ReDemo(root)
+ root.protocol('WM_DELETE_WINDOW', root.quit)
+ root.mainloop()
+
+if __name__ == '__main__':
+ main()