• 1000 1004 *
См. Сценарий python ниже:
"""Attach parent to children in an indentation-structured text"""
from typing import Tuple, List
import sys
# A unique separator to separate the parent and child in each line
SEPARATOR = '@'
# The indentation
INDENT = ' '
def parse_line(line: str) -> Tuple[int, str]:
"""Parse a line into indentation level and its content
with indentation stripped
Args:
line (str): One of the lines from the input file, with newline ending
Returns:
Tuple[int, str]: The indentation level and the content with
indentation stripped.
Raises:
ValueError: If the line is incorrectly indented.
"""
# strip the leading white spaces
lstripped_line = line.lstrip()
# get the indentation
indent = line[:-len(lstripped_line)]
# Let's check if the indentation is correct
# meaning it should be N * INDENT
n = len(indent) // len(INDENT)
if INDENT * n != indent:
raise ValueError(f"Wrong indentation of line: {line}")
return n, lstripped_line.rstrip('\r\n')
def format_text(txtfile: str) -> List[str]:
"""Format the text file by attaching the parent to it children
Args:
txtfile (str): The text file
Returns:
List[str]: A list of formatted lines
"""
formatted = []
par_indent = par_line = None
with open(txtfile) as ftxt:
for line in ftxt:
# get the indentation level and line without indentation
indent, line_noindent = parse_line(line)
# level 1 parents
if indent == 0:
par_indent = indent
par_line = line_noindent
formatted.append(line_noindent)
# children
elif indent > par_indent:
formatted.append(par_line +
SEPARATOR * (indent - par_indent) +
line_noindent)
par_indent = indent
par_line = par_line + SEPARATOR + line_noindent
# siblings or dedentation
else:
# We just need first `indent` parts of parent line as our prefix
prefix = SEPARATOR.join(par_line.split(SEPARATOR)[:indent])
formatted.append(prefix + SEPARATOR + line_noindent)
par_indent = indent
par_line = prefix + SEPARATOR + line_noindent
return formatted
def sort_and_revert(lines: List[str]):
"""Sort the formatted lines and revert the leading parents
into indentations
Args:
lines (List[str]): list of formatted lines
Prints:
The sorted and reverted lines
"""
sorted_lines = sorted(lines)
for line in sorted_lines:
if SEPARATOR not in line:
print(line)
else:
leading, _, orig_line = line.rpartition(SEPARATOR)
print(INDENT * (leading.count(SEPARATOR) + 1) + orig_line)
def main():
"""Main entry"""
if len(sys.argv) < 2:
print(f"Usage: {sys.argv[0]} <file>")
sys.exit(1)
formatted = format_text(sys.argv[1])
sort_and_revert(formatted)
if __name__ == "__main__":
main()
Давайте сохраним его как format.py, и у нас есть тестовый файл, скажем test.txt:
parent2
child2-1
child2-1-1
child2-2
parent1
child1-2
child1-2-2
child1-2-1
child1-1
Давайте проверим это:
$ python format.py test.txt
parent1
child1-1
child1-2
child1-2-1
child1-2-2
parent2
child2-1
child2-1-1
child2-2
Если вам интересно, как функция format_text форматирует текст, вот промежуточные результаты, которые также объясняют, почему мы можем отсортировать файл так, как мы хотели:
parent2
parent2@child2-1
parent2@child2-1@child2-1-1
parent2@child2-2
parent1
parent1@child1-2
parent1@child1-2@child1-2-2
parent1@child1-2@child1-2-1
parent1@child1-1
Вы можете видеть, что у каждого ребенка есть свои родители, вплоть до root. Чтобы потомки одного родителя были отсортированы вместе.