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Accepted
Vadim Yermolenko
Asked:2020-03-12 18:39:23 +0000 UTC2020-03-12 18:39:23 +0000 UTC

如何将文件中的行从一个关键字删除到另一个关键字？

  • 772

我有一个包含以下内容的文件：

        CREATE TABLE some_name (
fv int,
sv int,
tv int)
CLUSTERED BY (fv,
              sv,
              tv) 
SORTED BY (fv,
           sv,
           tv) INTO 2 BUCKETS;
-- more text afterwards

例如，我需要确保脚本会删除从 Clustered inclusive 到 Buckets inclusive 的所有单词，但不会删除分号。代码如何实现？我被提供了这个：

start_word = "CLUSTERED"
end_word = "BUCKETS"

result_lines = []

with open(target_file, 'r') as f:
    erasing = False
    for line in f:
        if not erasing and start_word in line:
            // begin erasing lines
            erasing = True
            continue

        if erasing and end_word in line:
            // finished erasing lines
            erasing = False
            continue

        if erasing:
            // we are between the start and end of the section we want to erase
            continue
        else:
            // either we haven't started erasing or we have already finished
            result_lines.append(line)

print('\n'.join(result_lines))

但它会删除分号，一般来说，所有与 Clustered 和 Buckets 一致的东西都会被删除。结果应该是这样的：

 CREATE TABLE some_name (
fv int,
sv int,
tv int)
-- more text afterwards;
python

2 个回答

  1. Best Answer

    使用正则表达式：

    import re

#text = """
#CREATE TABLE some_name (
#fv int,
#sv int,
#tv int)
#CLUSTERED BY (fv,
#              sv,
#              tv) 
#SORTED BY (fv,
#           sv,
#           tv) INTO 2 BUCKETS;
#-- more text afterwards
#"""

with open(target_file, 'r') as f:
    text = f.read()
res = re.sub('CLUSTERED[\s\b\n\r]+[^;]*', '', text)
print(res)

    CREATE TABLE some_name (
fv int,
sv int,
tv int)
;
-- more text afterwards
    • 3

  2. 带有正则表达式的示例：

    import re

text = """\
CREATE TABLE some_name (
fv int,
sv int,
tv int)
CLUSTERED BY (fv,
              sv,
              tv) 
SORTED BY (fv,
           sv,
           tv) INTO 2 BUCKETS;
-- more text afterwards
"""

new_text = re.sub('Clustered.+?Buckets;', ';', text, flags=re.I | re.DOTALL)
print(new_text)

    结果：

    CREATE TABLE some_name (
fv int,
sv int,
tv int)
;
-- more text afterwards
    • 1

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