📜  Python向后读取文件

📅  最后修改于: 2020-11-06 06:15:21             🧑  作者: Mango


通常,当我们读取文件时,将从文件的开头逐行读取内容。但是在某些情况下,我们想先阅读最后一行。例如,文件中的数据在底部具有最新记录,我们希望首先读取最新记录。为了达到此要求,我们使用下面的命令安装所需的软件包以执行此操作。

pip install file-read-backwards 

但是在向后读取文件之前,让我们逐行读取文件的内容,以便可以在向后读取之后比较结果。

with open ("Path\GodFather.txt", "r") as BigFile:
    data=BigFile.readlines()

# Print each line
    for i in range(len(data)):
    print "Line No- ",i 
    print data[i]

当我们运行上面的程序时,我们得到以下输出-

Line No-  0
Vito Corleone is the aging don (head) of the Corleone Mafia Family. 

Line No-  1
His youngest son Michael has returned from WWII just in time to see the wedding of Connie Corleone (Michael's sister) to Carlo Rizzi. 

Line No-  2
All of Michael's family is involved with the Mafia, but Michael just wants to live a normal life. Drug dealer Virgil Sollozzo is looking for Mafia families to offer him protection in exchange for a profit of the drug money. 

Line No-  3
He approaches Don Corleone about it, but, much against the advice of the Don's lawyer Tom Hagen, the Don is morally against the use of drugs, and turns down the offer.

Line No-  4
This does not please Sollozzo, who has the Don shot down by some of his hit men. 

Line No-  5
The Don barely survives, which leads his son Michael to begin a violent mob war against Sollozzo and tears the Corleone family apart.

向后读线

现在,向后读取文件,我们使用已安装的模块。

from file_read_backwards import FileReadBackwards

with FileReadBackwards("Path\GodFather.txt", encoding="utf-8") as BigFile:

# getting lines by lines starting from the last line up
    for line in BigFile:
        print line

当我们运行上面的程序时,我们得到以下输出-

The Don barely survives, which leads his son Michael to begin a violent mob war against Sollozzo and tears the Corleone family apart.
This does not please Sollozzo, who has the Don shot down by some of his hit men. 
He approaches Don Corleone about it, but, much against the advice of the Don's lawyer Tom Hagen, the Don is morally against the use of drugs, and turns down the offer.
All of Michael's family is involved with the Mafia, but Michael just wants to live a normal life. Drug dealer Virgil Sollozzo is looking for Mafia families to offer him protection in exchange for a profit of the drug money. 
His youngest son Michael has returned from WWII just in time to see the wedding of Connie Corleone (Michael's sister) to Carlo Rizzi. 
Vito Corleone is the aging don (head) of the Corleone Mafia Family. 

您可以验证以相反的顺序读取了行。

向后读单词

我们还可以向后读取文件中的单词。为此,我们首先向后读取行,然后使用反向函数将其中的单词标记化。在下面的示例中,我们使用package和nltk模块将单词令牌从同一文件向后打印。

import nltk
from file_read_backwards import FileReadBackwards

with FileReadBackwards("Path\GodFather.txt", encoding="utf-8") as BigFile:

# getting lines by lines starting from the last line up
# And tokenizing with applying reverse()
    for line in BigFile:
        word_data= line
        nltk_tokens = nltk.word_tokenize(word_data)
        nltk_tokens.reverse()
        print (nltk_tokens)

当我们运行上面的程序时,我们得到以下输出-

['.', 'apart', 'family', 'Corleone', 'the', 'tears', 'and', 'Sollozzo', 'against', 'war', 'mob', 'violent', 'a', 'begin', 'to', 'Michael', 'son', 'his', 'leads', 'which', ',', 'srvives', 'barely', 'Don', 'The']
['.', 'men', 'hit', 'his', 'of', 'some', 'by', 'down', 'shot', 'Don', 'the', 'has', 'who', ',', 'Sollozzo', 'please', 'not', 'does', 'This']
['.', 'offer', 'the', 'down', 'trns', 'and', ',', 'drgs', 'of', 'se', 'the', 'against', 'morally', 'is', 'Don', 'the', ',', 'Hagen', 'Tom', 'lawyer', "'s", 'Don', 'the', 'of', 'advice', 'the', 'against', 'mch', ',', 'bt', ',', 'it', 'abot', 'Corleone', 'Don', 'approaches', 'He']
['.', 'money', 'drg', 'the', 'of', 'profit', 'a', 'for', 'exchange', 'in', 'protection', 'him', 'offer', 'to', 'families', 'Mafia', 'for', 'looking', 'is', 'Sollozzo', 'Virgil', 'dealer', 'Drg', '.', 'life', 'normal', 'a', 'live', 'to', 'wants', 'jst', 'Michael', 'bt', ',', 'Mafia', 'the', 'with', 'involved', 'is', 'family', "'s", 'Michael', 'of', 'All']
['.', 'Rizzi', 'Carlo', 'to', ')', 'sister', "'s", 'Michael', '(', 'Corleone', 'Connie', 'of', 'wedding', 'the', 'see', 'to', 'time', 'in', 'jst', 'WWII', 'from', 'retrned', 'has', 'Michael', 'son', 'yongest', 'His']
['.', 'Family', 'Mafia', 'Corleone', 'the', 'of', ')', 'head', '(', 'don', 'aging', 'the', 'is', 'Corleone', 'Vito']