asciiWriter/asciiWriter/wrap_single_line.py

137 lines
5.3 KiB
Python

"""
Based on the textwrap2 module included in the PyHyphen library:
https://pypi.org/project/PyHyphen
"""
import textwrap
class TextWrapper(textwrap.TextWrapper):
"""
This class extends the Python 3 standard library's TextWrapper and adds an optional
use_hyphenator to its constructor arguments.
"""
def __init__(self, *args, **kwargs):
self.use_hyphenator = kwargs.pop("use_hyphenator", None)
super().__init__(*args, **kwargs)
def _wrap_chunks(self, chunks):
lines = []
if (chunks):
"""Override the mother class method.
Most of that method is directly copied from the original class, except
for the part with use_hyphenator.
"""
if self.width <= 0:
raise ValueError("invalid width %r (must be > 0)" % self.width)
if self.max_lines is not None:
if self.max_lines > 1:
indent = self.subsequent_indent
else:
indent = self.initial_indent
if len(indent) + len(self.placeholder.lstrip()) > self.width:
raise ValueError("placeholder too large for max width")
# Arrange in reverse order so items can be efficiently popped
# from a stack of chucks.
chunks.reverse()
# Start the list of chunks that will make up the current line.
# cur_len is just the length of all the chunks in cur_line.
cur_line = []
cur_len = 0
# Figure out which static string will prefix this line.
if lines:
indent = self.subsequent_indent
else:
indent = self.initial_indent
# Maximum width for this line.
width = self.width - len(indent)
# First chunk on line is whitespace -- drop it, unless this
# is the very beginning of the text (ie. no lines started yet).
if self.drop_whitespace and chunks[-1].strip() == '' and chunks[-1][0] != '\n': # and lines:
del chunks[-1]
while chunks:
l = len(chunks[-1])
# Check for a newline character
if chunks[-1] == '\n':
return indent + ''.join(cur_line), ''.join(reversed(chunks[:-1]))
elif chunks[-1][0] == '\n':
return indent + ''.join(cur_line), ''.join(reversed(chunks[:-1] + [chunks[-1][1:]]))
# Can at least squeeze this chunk onto the current line.
if cur_len + l <= width:
cur_line.append(chunks.pop())
cur_len += l
# Nope, this line is full.
# But try hyphenation.
else:
if self.use_hyphenator and (width - cur_len >= 2):
hyphenated_chunk = self.use_hyphenator.wrap(chunks[-1], width - cur_len)
if hyphenated_chunk:
cur_line.append(hyphenated_chunk[0])
chunks[-1] = hyphenated_chunk[1]
break
# The current line is full, and the next chunk is too big to
# fit on *any* line (not just this one).
if chunks and len(chunks[-1]) > width:
self._handle_long_word(chunks, cur_line, cur_len, width)
cur_len = sum(map(len, cur_line))
# If the last chunk on this line is all whitespace, drop it.
if self.drop_whitespace and cur_line and cur_line[-1].strip() == '':
cur_len -= len(cur_line[-1])
del cur_line[-1]
if cur_line:
if (self.max_lines is None or
len(lines) + 1 < self.max_lines or
(not chunks or
self.drop_whitespace and
len(chunks) == 1 and
not chunks[0].strip()) and cur_len <= width):
# Convert current line back to a string and store it in
# list of all lines (return value).
return indent + ''.join(cur_line), ''.join(reversed(chunks))
else:
while cur_line:
if (cur_line[-1].strip() and
cur_len + len(self.placeholder) <= width):
cur_line.append(self.placeholder)
return indent + ''.join(cur_line), ''.join(reversed(chunks))
cur_len -= len(cur_line[-1])
del cur_line[-1]
else:
if lines:
prev_line = lines[-1].rstrip()
if (len(prev_line) + len(self.placeholder) <=
self.width):
lines[-1] = prev_line + self.placeholder
return indent + self.placeholder.lstrip(), ''.join(reversed(chunks))
else:
return '', ''
def wrap_single_line (text, width=70, **kwargs):
w = TextWrapper(width=width, **kwargs)
return w.wrap(text)
if __name__ == '__main__':
from hyphen import Hyphenator
h_en = Hyphenator('en_US')
line, remaining = wrap_single_line('https://stackoverflow.com/questions/3940128/how-can-i-reverse-a-list-in-python', width=46, use_hyphenator=h_en)
print(line, remaining)