要在此示例中提取文本的某個部分，我想從 d 提取到 finput.txt 包含：adcbefgaaoutput.txt 應該包含從 d 到 f 但這個程序從 d 復制到 input.txt 文件的最后一行f = open('input.txt')f1 = open('output.txt', 'a')intermediate_variable=Falsefor line in f: if 'd' in line: intermediate_variable=True if intermediate_variable==True: f1.write(line)f1.close()f.close()
3 回答
明月笑刀無情
TA貢獻1828條經驗 獲得超4個贊
我認為應該這樣做：
contents = open('input.txt').read()
f1.write(contents[contents.index("d"):contents.index("f")])
慕俠2389804
TA貢獻1719條經驗 獲得超6個贊
有更方便的方式來讀寫文件，這個版本使用了一個生成器和'with'關鍵字（上下文管理器），它會自動為你關閉文件。生成器（帶有 'yield' 的函數很好，因為它們一次給你一行文件，盡管你必須將它們的輸出包裝在 try/except 塊中）
def reader(filename):
with open(filename, 'r') as fin:
for line in fin:
yield line
def writer(filename, data):
with open(filename, 'w') as fout: #change 'w' to 'a' to append ('w' overwrites)
fout.write(data)
if __name__ == "__main__":
a = reader("input.txt")
while True:
try:
temp = next(a)
if 'd' in temp:
#this version of above answer captures the 'f' as well
writer("output.txt", temp[temp.index('d'):temp.index('f') + 1])
except StopIteration:
break
米脂
TA貢獻1836條經驗 獲得超3個贊
直截了當：
### load all the data at once, fine for small files:
with open('input.txt', 'r') as f:
content = f.read().splitlines() ## use f.readlines() to have the newline chars included
### slice what you need from content:
selection = content[content.index("d"):content.index("f")]
## use content.index("f")+1 to include "f" in the output.
### write selection to output:
with open('output.txt', 'a') as f:
f.write('\n'.join(selection))
## or:
# for line in selection:
# f.write(line + '\n')
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