blob: a381679fdb545912b2d1815f3e1c680e662587fd [file] [log] [blame]
#!/usr/bin/env python
"""Sort a simple YAML file, keeping blocks of comments and definitions
We assume a strict subset of YAML that looks like:
# block of header comments
# here that should always
# be at the top of the file
# optional comments
# can go here
key: value
key: value
key: value
In other words, we don't sort deeper than the top layer, and might corrupt
complicated YAML files.
from __future__ import print_function
import argparse
from typing import List
from typing import Optional
from typing import Sequence
QUOTES = ["'", '"']
def sort(lines): # type: (List[str]) -> List[str]
"""Sort a YAML file in alphabetical order, keeping blocks together.
:param lines: array of strings (without newlines)
:return: sorted array of strings
# make a copy of lines since we will clobber it
lines = list(lines)
new_lines = parse_block(lines, header=True)
for block in sorted(parse_blocks(lines), key=first_key):
if new_lines:
return new_lines
def parse_block(lines, header=False): # type: (List[str], bool) -> List[str]
"""Parse and return a single block, popping off the start of `lines`.
If parsing a header block, we stop after we reach a line that is not a
comment. Otherwise, we stop after reaching an empty line.
:param lines: list of lines
:param header: whether we are parsing a header block
:return: list of lines that form the single block
block_lines = []
while lines and lines[0] and (not header or lines[0].startswith('#')):
return block_lines
def parse_blocks(lines): # type: (List[str]) -> List[List[str]]
"""Parse and return all possible blocks, popping off the start of `lines`.
:param lines: list of lines
:return: list of blocks, where each block is a list of lines
blocks = []
while lines:
if lines[0] == '':
return blocks
def first_key(lines): # type: (List[str]) -> str
"""Returns a string representing the sort key of a block.
The sort key is the first YAML key we encounter, ignoring comments, and
stripping leading quotes.
>>> print(test)
# some comment
'foo': true
>>> first_key(test)
for line in lines:
if line.startswith('#'):
if any(line.startswith(quote) for quote in QUOTES):
return line[1:]
return line
return '' # not actually reached in reality
def main(argv=None): # type: (Optional[Sequence[str]]) -> int
parser = argparse.ArgumentParser()
parser.add_argument('filenames', nargs='*', help='Filenames to fix')
args = parser.parse_args(argv)
retval = 0
for filename in args.filenames:
with open(filename, 'r+') as f:
lines = [line.rstrip() for line in f.readlines()]
new_lines = sort(lines)
if lines != new_lines:
print('Fixing file `{filename}`'.format(filename=filename))
f.write('\n'.join(new_lines) + '\n')
retval = 1
return retval
if __name__ == '__main__':