Added support for printing out help text from option table: 'print_help()',

'generate_help()', 'wrap_text()' functions, and a little tiny test
  of 'wrap_text()'.
Changed how caller states that one option is the boolean opposite of
  another: added 'negative_opt' parameter to 'fancy_getopt()', and changed
  to use it instead of parsing long option name.
This commit is contained in:
Greg Ward 1999-12-12 16:54:55 +00:00
parent c9c37b1c6e
commit 44f8e4ea08

View file

@ -12,7 +12,7 @@
__rcsid__ = "$Id$"
import string, re
import sys, string, re
from types import *
import getopt
from distutils.errors import *
@ -33,7 +33,7 @@
longopt_xlate = string.maketrans ('-', '_')
def fancy_getopt (options, object, args):
def fancy_getopt (options, negative_opt, object, args):
# The 'options' table is a list of 3-tuples:
# (long_option, short_option, help_string)
@ -51,7 +51,6 @@ def fancy_getopt (options, object, args):
short2long = {}
attr_name = {}
takes_arg = {}
neg_alias = {}
for option in options:
try:
@ -81,18 +80,15 @@ def fancy_getopt (options, object, args):
else:
# Is option is a "negative alias" for some other option (eg.
# "quiet=!verbose")?
match = neg_alias_re.match (long)
if match:
(alias_from, alias_to) = match.group (1,2)
# "quiet" == "!verbose")?
alias_to = negative_opt.get(long)
if alias_to is not None:
if not takes_arg.has_key(alias_to) or takes_arg[alias_to]:
raise DistutilsGetoptError, \
("option '%s' is a negative alias for '%s', " +
"which either hasn't been defined yet " +
"or takes an argument") % (alias_from, alias_to)
"or takes an argument") % (long, alias_to)
long = alias_from
neg_alias[long] = alias_to
long_opts[-1] = long
takes_arg[long] = 0
@ -137,7 +133,7 @@ def fancy_getopt (options, object, args):
setattr (object, attr, val)
else:
if val == '':
alias = neg_alias.get (opt)
alias = negative_opt.get (opt)
if alias:
setattr (object, attr_name[alias], 0)
else:
@ -149,4 +145,167 @@ def fancy_getopt (options, object, args):
return args
# end fancy_getopt()
# fancy_getopt()
WS_TRANS = string.maketrans (string.whitespace, ' ' * len (string.whitespace))
def wrap_text (text, width):
if text is None:
return []
if len (text) <= width:
return [text]
text = string.expandtabs (text)
text = string.translate (text, WS_TRANS)
chunks = re.split (r'( +|-+)', text)
chunks = filter (None, chunks) # ' - ' results in empty strings
lines = []
while chunks:
cur_line = [] # list of chunks (to-be-joined)
cur_len = 0 # length of current line
while chunks:
l = len (chunks[0])
if cur_len + l <= width: # can squeeze (at least) this chunk in
cur_line.append (chunks[0])
del chunks[0]
cur_len = cur_len + l
else: # this line is full
# drop last chunk if all space
if cur_line and cur_line[-1][0] == ' ':
del cur_line[-1]
break
if chunks: # any chunks left to process?
# if the current line is still empty, then we had a single
# chunk that's too big too fit on a line -- so we break
# down and break it up at the line width
if cur_len == 0:
cur_line.append (chunks[0][0:width])
chunks[0] = chunks[0][width:]
# all-whitespace chunks at the end of a line can be discarded
# (and we know from the re.split above that if a chunk has
# *any* whitespace, it is *all* whitespace)
if chunks[0][0] == ' ':
del chunks[0]
# and store this line in the list-of-all-lines -- as a single
# string, of course!
lines.append (string.join (cur_line, ''))
# while chunks
return lines
# wrap_text ()
def generate_help (options, header=None):
"""Generate help text (a list of strings, one per suggested line of
output) from an option table."""
# Blithely assume the option table is good: probably wouldn't call
# 'generate_help()' unless you've already called 'fancy_getopt()'.
# First pass: determine maximum length of long option names
max_opt = 0
for option in options:
long = option[0]
short = option[1]
l = len (long)
if long[-1] == '=':
l = l - 1
if short is not None:
l = l + 5 # " (-x)" where short == 'x'
if l > max_opt:
max_opt = l
opt_width = max_opt + 2 + 2 + 2 # room for indent + dashes + gutter
# Typical help block looks like this:
# --foo controls foonabulation
# Help block for longest option looks like this:
# --flimflam set the flim-flam level
# and with wrapped text:
# --flimflam set the flim-flam level (must be between
# 0 and 100, except on Tuesdays)
# Options with short names will have the short name shown (but
# it doesn't contribute to max_opt):
# --foo (-f) controls foonabulation
# If adding the short option would make the left column too wide,
# we push the explanation off to the next line
# --flimflam (-l)
# set the flim-flam level
# Important parameters:
# - 2 spaces before option block start lines
# - 2 dashes for each long option name
# - min. 2 spaces between option and explanation (gutter)
# - 5 characters (incl. space) for short option name
# Now generate lines of help text.
line_width = 78 # if 80 columns were good enough for
text_width = line_width - opt_width # Jesus, then 78 are good enough for me
big_indent = ' ' * opt_width
if header:
lines = [header]
else:
lines = ['Option summary:']
for (long,short,help) in options:
text = wrap_text (help, text_width)
if long[-1] == '=':
long = long[0:-1]
# Case 1: no short option at all (makes life easy)
if short is None:
if text:
lines.append (" --%-*s %s" % (max_opt, long, text[0]))
else:
lines.append (" --%-*s " % (max_opt, long))
for l in text[1:]:
lines.append (big_indent + l)
# Case 2: we have a short option, so we have to include it
# just after the long option
else:
opt_names = "%s (-%s)" % (long, short)
if text:
lines.append (" --%-*s %s" %
(max_opt, opt_names, text[0]))
else:
lines.append (" --%-*s" % opt_names)
# for loop over options
return lines
# generate_help ()
def print_help (options, file=None, header=None):
if file is None:
file = sys.stdout
for line in generate_help (options, header):
file.write (line + "\n")
# print_help ()
if __name__ == "__main__":
text = """\
Tra-la-la, supercalifragilisticexpialidocious.
How *do* you spell that odd word, anyways?
(Someone ask Mary -- she'll know [or she'll
say, "How should I know?"].)"""
for w in (10, 20, 30, 40):
print "width: %d" % w
print string.join (wrap_text (text, w), "\n")
print