正常讀取檔案時，從檔案開頭逐行讀取內容。 但是有些情況下我們想先讀取最後一行。 例如，檔案中的資料底部有最新記錄，需要先讀取最新記錄。 為了達到此要求，可使用以下命令安裝所需的包以執行此操作。
pip install file-read-backwards
但是在向後讀取檔案之前，我們先逐行讀取檔案的內容，以便可以在向後讀取後可以作比較。
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]
當我們執行上面的程式時，得到以下輸出 -
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.
現在要向後讀取檔案，這裡使用上面已安裝的模組 - file-read-backwards。
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
當執行上面的程式時，得到以下輸出 -
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.
可以按相反順序驗證已讀取的行。
我們也可以向後閱讀檔案中的單詞。首先向後讀取行，然後使用reverse()函式對其中的單詞進行標記。 在下面的範例中，使用nltk模組將向後列印的單詞標記形成為同一檔案。
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)
執行上面範例程式碼，得到以下結果 -
['.', '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']