2023-02-24 13:30:00 -06:00
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# Exercise 9
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2023-03-03 12:49:43 -06:00
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# sed command
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2023-02-24 13:30:00 -06:00
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import re
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import sys
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import argparse
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from pathlib import Path
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def check(expression, exp):
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error = False
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if (
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expression[-1] not in "/g"
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or exp[0] not in "s"
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or len(exp) not in range(3, 5)
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or (expression[-1] in "g" and len(exp) != 4)
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or (expression[-1] in "/" and len(exp) == 4)
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):
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error = True
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if error:
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print(f"sed: expresión «{expression}» inválida")
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sys.exit(1)
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def parse(expression):
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count = 0
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exp = list(filter(None, expression.split("/")))
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check(expression, exp)
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if len(exp) == 3:
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count = 1
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return {
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"rgx": re.compile(exp[1]),
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"rep": exp[2],
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"n": count,
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}
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parser = argparse.ArgumentParser()
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parser.add_argument("stream", default=sys.stdin, nargs="*")
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parser.add_argument(
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"-e", "--expression", required=True, type=str, action="append"
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)
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args = parser.parse_args()
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res = ""
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for exp in args.expression:
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exp = parse(exp)
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for stream in args.stream:
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if isinstance(args.stream, list):
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stream = Path(stream).read_text()
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else:
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stream = stream.strip()
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if res == "":
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res = stream
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res = re.sub(exp["rgx"], exp["rep"], res, count=exp["n"])
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print(res)
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