1 #!/usr/bin/env python3
2
3 """Basic regular expression demonstration facility (Perl style syntax)."""
4
5 from tkinter import *
6 import re
7
8 class ESC[4;38;5;81mReDemo:
9
10 def __init__(self, master):
11 self.master = master
12
13 self.promptdisplay = Label(self.master, anchor=W,
14 text="Enter a Perl-style regular expression:")
15 self.promptdisplay.pack(side=TOP, fill=X)
16
17 self.regexdisplay = Entry(self.master)
18 self.regexdisplay.pack(fill=X)
19 self.regexdisplay.focus_set()
20
21 self.addoptions()
22
23 self.statusdisplay = Label(self.master, text="", anchor=W)
24 self.statusdisplay.pack(side=TOP, fill=X)
25
26 self.labeldisplay = Label(self.master, anchor=W,
27 text="Enter a string to search:")
28 self.labeldisplay.pack(fill=X)
29 self.labeldisplay.pack(fill=X)
30
31 self.showframe = Frame(master)
32 self.showframe.pack(fill=X, anchor=W)
33
34 self.showvar = StringVar(master)
35 self.showvar.set("first")
36
37 self.showfirstradio = Radiobutton(self.showframe,
38 text="Highlight first match",
39 variable=self.showvar,
40 value="first",
41 command=self.recompile)
42 self.showfirstradio.pack(side=LEFT)
43
44 self.showallradio = Radiobutton(self.showframe,
45 text="Highlight all matches",
46 variable=self.showvar,
47 value="all",
48 command=self.recompile)
49 self.showallradio.pack(side=LEFT)
50
51 self.stringdisplay = Text(self.master, width=60, height=4)
52 self.stringdisplay.pack(fill=BOTH, expand=1)
53 self.stringdisplay.tag_configure("hit", background="yellow")
54
55 self.grouplabel = Label(self.master, text="Groups:", anchor=W)
56 self.grouplabel.pack(fill=X)
57
58 self.grouplist = Listbox(self.master)
59 self.grouplist.pack(expand=1, fill=BOTH)
60
61 self.regexdisplay.bind('<Key>', self.recompile)
62 self.stringdisplay.bind('<Key>', self.reevaluate)
63
64 self.compiled = None
65 self.recompile()
66
67 btags = self.regexdisplay.bindtags()
68 self.regexdisplay.bindtags(btags[1:] + btags[:1])
69
70 btags = self.stringdisplay.bindtags()
71 self.stringdisplay.bindtags(btags[1:] + btags[:1])
72
73 def addoptions(self):
74 self.frames = []
75 self.boxes = []
76 self.vars = []
77 for name in ('IGNORECASE',
78 'MULTILINE',
79 'DOTALL',
80 'VERBOSE'):
81 if len(self.boxes) % 3 == 0:
82 frame = Frame(self.master)
83 frame.pack(fill=X)
84 self.frames.append(frame)
85 val = getattr(re, name).value
86 var = IntVar()
87 box = Checkbutton(frame,
88 variable=var, text=name,
89 offvalue=0, onvalue=val,
90 command=self.recompile)
91 box.pack(side=LEFT)
92 self.boxes.append(box)
93 self.vars.append(var)
94
95 def getflags(self):
96 flags = 0
97 for var in self.vars:
98 flags = flags | var.get()
99 return flags
100
101 def recompile(self, event=None):
102 try:
103 self.compiled = re.compile(self.regexdisplay.get(),
104 self.getflags())
105 bg = self.promptdisplay['background']
106 self.statusdisplay.config(text="", background=bg)
107 except re.error as msg:
108 self.compiled = None
109 self.statusdisplay.config(
110 text="re.error: %s" % str(msg),
111 background="red")
112 self.reevaluate()
113
114 def reevaluate(self, event=None):
115 try:
116 self.stringdisplay.tag_remove("hit", "1.0", END)
117 except TclError:
118 pass
119 try:
120 self.stringdisplay.tag_remove("hit0", "1.0", END)
121 except TclError:
122 pass
123 self.grouplist.delete(0, END)
124 if not self.compiled:
125 return
126 self.stringdisplay.tag_configure("hit", background="yellow")
127 self.stringdisplay.tag_configure("hit0", background="orange")
128 text = self.stringdisplay.get("1.0", END)
129 last = 0
130 nmatches = 0
131 while last <= len(text):
132 m = self.compiled.search(text, last)
133 if m is None:
134 break
135 first, last = m.span()
136 if last == first:
137 last = first+1
138 tag = "hit0"
139 else:
140 tag = "hit"
141 pfirst = "1.0 + %d chars" % first
142 plast = "1.0 + %d chars" % last
143 self.stringdisplay.tag_add(tag, pfirst, plast)
144 if nmatches == 0:
145 self.stringdisplay.yview_pickplace(pfirst)
146 groups = list(m.groups())
147 groups.insert(0, m.group())
148 for i in range(len(groups)):
149 g = "%2d: %r" % (i, groups[i])
150 self.grouplist.insert(END, g)
151 nmatches = nmatches + 1
152 if self.showvar.get() == "first":
153 break
154
155 if nmatches == 0:
156 self.statusdisplay.config(text="(no match)",
157 background="yellow")
158 else:
159 self.statusdisplay.config(text="")
160
161
162 # Main function, run when invoked as a stand-alone Python program.
163
164 def main():
165 root = Tk()
166 demo = ReDemo(root)
167 root.protocol('WM_DELETE_WINDOW', root.quit)
168 root.mainloop()
169
170 if __name__ == '__main__':
171 main()