Use a text widget with word wrapping, and either define your string more accurately or do a little post-processing to remove all that extra whitespace. Using the code from this answer makes it easy to use multiple colors, fonts, etc.
For example:
import Tkinter as tk
import re
class CustomText(tk.Text):
'''A text widget with a new method, HighlightPattern
example:
text = CustomText()
text.tag_configure("red",foreground="#ff0000")
text.HighlightPattern("this should be red", "red")
The HighlightPattern method is a simplified python
version of the tcl code at http://wiki.tcl.tk/3246
'''
def __init__(self, *args, **kwargs):
tk.Text.__init__(self, *args, **kwargs)
def HighlightPattern(self, pattern, tag, start="1.0", end="end", regexp=True):
'''Apply the given tag to all text that matches the given pattern'''
start = self.index(start)
end = self.index(end)
self.mark_set("matchStart",start)
self.mark_set("matchEnd",end)
self.mark_set("searchLimit", end)
count = tk.IntVar()
while True:
index = self.search(pattern, "matchEnd","searchLimit",count=count, regexp=regexp)
if index == "": break
self.mark_set("matchStart", index)
self.mark_set("matchEnd", "%s+%sc" % (index,count.get()))
self.tag_add(tag, "matchStart","matchEnd")
def aboutF():
win = tk.Toplevel()
win.title("About")
about = '''Top/bottom 3 - Reports only the top/bottom 3 rows for a param you will later specify.
Set noise threshold - Filters results with deltas below the specified noise threshold in ps.
Sort output - Sorts by test,pre,post,unit,delta,abs(delta).
Top 2 IDD2P/IDD6 registers - Reports only the top 2 IDD2P/IDD6 registers.
Only critical registers - Reports only critical registers.
Use tilda output format - Converts the output file from csv to tilda.
Use html output format - Converts the output file from csv to html.'''
about = re.sub("\n\s*", "\n", about) # remove leading whitespace from each line
t=CustomText(win, wrap="word", width=100, height=10, borderwidth=0)
t.tag_configure("blue", foreground="blue")
t.pack(sid="top",fill="both",expand=True)
t.insert("1.0", about)
t.HighlightPattern("^.*? - ", "blue")
tk.Button(win, text='OK', command=win.destroy).pack()
root=tk.Tk()
aboutF()
root.mainloop()