我对自己的base64编码实现有问题。我已经实现了以下代码。我认为它只适用于带有英文字母的文本文件。例如，pdf文件被编码和解码，它不同于单个字符。
def base64Encode(data):
alphabet = ["A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P","Q","R","S","T","U","V","W","X","Y","Z","a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z","0","1","2","3","4","5","6","7","8","9","+","/"]
bit_str = ""
base64_str = ""
for char in data:
bin_char = bin(char).lstrip("0b")
bin_char = bin_char.zfill(8)
bit_str += bin_char
brackets = [bit_str[x:x+6] for x in range(0,len(bit_str),6)]
for bracket in brackets:
if(len(bracket) < 6):
bracket = bracket + (6-len(bracket))*"0"
base64_str += alphabet[int(bracket,2)]
# print(brackets[-4:])
#if(bracket[-1:)
#print(len(base64_str))
#if(len(base64_str) != 76):
# base64_str += "="
return base64_str
def base64Decode(text):
alphabet = ["A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z","a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z","0","1","2","3","4","5","6","7","8","9","+","/"]
bit_str = ""
text_str = ""
for char in text:
if char in alphabet:
bin_char = bin(alphabet.index(char)).lstrip("0b")
bin_char = bin_char.zfill(6)
bit_str += bin_char
brackets = [bit_str[x:x+8] for x in range(0,len(bit_str),8)]
for bracket in brackets:
text_str += chr(int(bracket,2))
return text_str.encode("UTF-8")
w = open("encode.txt", "w")
with open("bla.txt", "rb") as f:
byte = f.read(57)
while byte:
w.write(base64Encode(byte))
w.write("\n")
byte = f.read(57)
w.close()
f.close()
w = open("decode.txt", "wb")
with open("encode.txt", "r") as f:
byte = f.read(77)
while byte:
w.write(base64Decode(byte))
byte = f.read(77)
w.close()
f.close()
在我看来，这行“return text_str.encode（”UTF-8“）”应该没有解码为UTF-8。但是，如果只留下“return text_str”，则会收到错误：TypeError：'str'不支持缓冲区接口。
bla.txt：
Phil Mercer reports on Cyclone Pam which has ravaged the Pacific nation of Vanuatu. Video courtesy of YouTube/Isso Nihmei at 350.org
Save the Children's Vanuatu country director Tom Skirrow said on Saturday: "The scene here this morning is complete devastation - houses are destroyed, trees are down, roads are blocked and people are wandering the streets looking for help.
ĄŚĆŹŻÓ
encode.txt
UGhpbCBNZXJjZXIgcmVwb3J0cyBvbiBDeWNsb25lIFBhbSB3aGljaCBoYXMgcmF2YWdlZCB0aGUg
UGFjaWZpYyBuYXRpb24gb2YgVmFudWF0dS4gVmlkZW8gY291cnRlc3kgb2YgWW91VHViZS9Jc3Nv
IE5paG1laSBhdCAzNTAub3JnDQoNClNhdmUgdGhlIENoaWxkcmVuJ3MgVmFudWF0dSBjb3VudHJ5
IGRpcmVjdG9yIFRvbSBTa2lycm93IHNhaWQgb24gU2F0dXJkYXk6ICJUaGUgc2NlbmUgaGVyZSB0
aGlzIG1vcm5pbmcgaXMgY29tcGxldGUgZGV2YXN0YXRpb24gLSBob3VzZXMgYXJlIGRlc3Ryb3ll
ZCwgdHJlZXMgYXJlIGRvd24sIHJvYWRzIGFyZSBibG9ja2VkIGFuZCBwZW9wbGUgYXJlIHdhbmRl
cmluZyB0aGUgc3RyZWV0cyBsb29raW5nIGZvciBoZWxwLg0KDQrEhMWaxIbFucW7w5M
decode.txt
Phil Mercer reports on Cyclone Pam which has ravaged the Pacific nation of Vanuatu. Video courtesy of YouTube/Isso Nihmei at 350.org
Save the Children's Vanuatu country director Tom Skirrow said on Saturday: "The scene here this morning is complete devastation - houses are destroyed, trees are down, roads are blocked and people are wandering the streets looking for help.
ÄÅÄŹŻÃ
由页面编码的相同文本：http://www.motobit.com/util/base64-decoder-encoder.asp
UGhpbCBNZXJjZXIgcmVwb3J0cyBvbiBDeWNsb25lIFBhbSB3aGljaCBoYXMgcmF2YWdlZCB0aGUg
UGFjaWZpYyBuYXRpb24gb2YgVmFudWF0dS4gVmlkZW8gY291cnRlc3kgb2YgWW91VHViZS9Jc3Nv
IE5paG1laSBhdCAzNTAub3JnDQoNClNhdmUgdGhlIENoaWxkcmVuJ3MgVmFudWF0dSBjb3VudHJ5
IGRpcmVjdG9yIFRvbSBTa2lycm93IHNhaWQgb24gU2F0dXJkYXk6ICJUaGUgc2NlbmUgaGVyZSB0
aGlzIG1vcm5pbmcgaXMgY29tcGxldGUgZGV2YXN0YXRpb24gLSBob3VzZXMgYXJlIGRlc3Ryb3ll
ZCwgdHJlZXMgYXJlIGRvd24sIHJvYWRzIGFyZSBibG9ja2VkIGFuZCBwZW9wbGUgYXJlIHdhbmRl
cmluZyB0aGUgc3RyZWV0cyBsb29raW5nIGZvciBoZWxwLg0KDQrEhMWaxIbFucW7w5M=
它是相同的，除了“=”，由于文件最开始的错误而省略了实现。
并以pdf格式化示例原始文件：
%PDF-1.5
%µµµµ
1 0 obj
<</Type/Catalog/Pages 2 0 R/Lang(pl-PL) /StructTreeRoot 8 0 R/MarkInfo<</Marked true>>>>
endobj
2 0 obj
<</Type/Pages/Count 1/Kids[ 3 0 R] >>
endobj
3 0 obj
<</Type/Page/Parent 2 0 R/Resources<</Font<</F1 5 0 R>>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 595.32 841.92] /Contents 4 0 R/Group<</Type/Group/S/Transparency/CS/DeviceRGB>>/Tabs/S/StructParents 0>>
endobj
4 0 obj
<</Filter/FlateDecode/Length 110>>
stream
xœUÌ
€@ྰï0QËÝ®Èiž?(†kb°hòý«ZD˜4ßÀΨ*;…¡xº ¨#“íªFrÄI!w…˜2ËQ81®D<™ÇS=Ó’léŠ82µ·>^åŒÊO- >[´SÀ
endstream
endobj
5 0 obj
<</Type/Font/Subtype/TrueType/Name/F1/BaseFont/ABCDEE+Calibri/Encoding/WinAnsiEncoding/FontDescriptor 6 0 R/FirstChar 32/LastChar 97/Widths 15 0 R>>
endobj
6 0 obj
<</Type/FontDescriptor/FontName/ABCDEE+Calibri/Flags 32/ItalicAngle 0/Ascent 750/Descent -250/CapHeight 750/AvgWidth 521/MaxWidth 1743/FontWeight 400/XHeight 250/StemV 52/FontBBox[ -503 -250 1240 750] /FontFile2 16 0 R>>
endobj
7 0 obj
执行脚本后：
%PDF-1.5
%µµµµ
1 0 obj
<</Type/Catalog/Pages 2 0 R/Lang(pl-PL) /StructTreeRoot 8 0 R/MarkInfo<</Marked true>>>>
endobj
2 0 obj
<</Type/Pages/Count 1/Kids[ 3 0 R] >>
endobj
3 0 obj
<</Type/Page/Parent 2 0 R/Resources<</Font<</F1 5 0 R>>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 595.32 841.92] /Contents 4 0 R/Group<</Type/Group/S/Transparency/CS/DeviceRGB>>/Tabs/S/StructParents 0>>
endobj
4 0 obj
<</Filter/FlateDecode/Length 110>>
stream
xUÌ
@ྰï0QËÝ®Èi?(kb°hòý«ZD4ßÀΨ*;¡xº ¨#íªFrÄI!w2ËQ81®D<ÇS=Ólé82µ·>^åÊO- >[´SÀ
endstream
endobj
5 0 obj
<</Type/Font/Subtype/TrueType/Name/F1/BaseFont/ABCDEE+Calibri/Encoding/WinAnsiEncoding/FontDescriptor 6 0 R/FirstChar 32/LastChar 97/Widths 15 0 R>>
endobj
6 0 obj
<</Type/FontDescriptor/FontName/ABCDEE+Calibri/Flags 32/ItalicAngle 0/Ascent 750/Descent -250/CapHeight 750/AvgWidth 521/MaxWidth 1743/FontWeight 400/XHeight 250/StemV 52/FontBBox[ -503 -250 1240 750] /FontFile2 16 0 R>>
endobj
7 0 obj
例如，差异在第15行和第16行的开头。
我的目标是加载文件并在base64中对其进行编码，然后解码并获取相同的文件。适合使用。我认为错误在数据读取或写入或编码中。有什么建议？
我的第一个建议是排除故障：确定您是否未能正确编码或解码或两者兼而有之。使用工作实用程序和您的应用程序对文件进行编码并进行比较。使用您的应用程序和工作实用程序解码正确编码的文件并进行比较。第二个建议：将数据作为单个字节处理，而不是可能被解释为UTF-8的文本。
以二进制模式打开PDF文件。请参阅Reading binary file in Python and looping over each byte了解如何做到这一点。将原始字节传递给base64Encode。不要使用bin函数将字符串转换为二进制。
我能够完成这项任务。替换.encode（“latin-1”）上的.encode（“UTF-8”）行，它至少适用于pdf文件。
我修改了原始代码。这适用于文本，PNG和PDF，我还没有尝试过其他文件类型，但我希望它能适用于它们。
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
Created on Sat Mar 16 07:38:19 2019
@author: tracyanne
"""
import os
class Base64():
def __init__(self):
## We only need to do this once
self.b64 = ["A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P","Q","R","S","T","U","V","W","X","Y","Z","a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z","0","1","2","3","4","5","6","7","8","9","+","/"]
def Encode(self, data):
alphabet = self.b64
bit_str = ""
base64_str = ""
for char in data:
bin_char = bin(char).lstrip("0b")
bin_char = bin_char.zfill(8)
bit_str += bin_char
brackets = [bit_str[x:x+6] for x in range(0,len(bit_str),6)]
for bracket in brackets:
if(len(bracket) < 6):
bracket = bracket + (6-len(bracket))*"0"
base64_str += alphabet[int(bracket,2)]
##Add padding characters to maintain compatibility with forced padding
padding_indicator = len(base64_str) % 4
if padding_indicator == 3:
base64_str += "="
elif padding_indicator == 2:
base64_str += "=="
return base64_str
def Decode(self, text, eof):
alphabet = self.b64
bit_str = ""
text_str = ""
for char in text:
if char in alphabet:
bin_char = bin(alphabet.index(char)).lstrip("0b")
bin_char = bin_char.zfill(6)
bit_str += bin_char
brackets = [bit_str[x:x+8] for x in range(0,len(bit_str),8)]
for bracket in brackets:
## When eof ignore last value in brackets to remove \x00
if eof and brackets[len(brackets) -1] == bracket:
pass
else:
text_str += chr(int(bracket,2))
## encode string as Latin-1 == ISO-8859-1
return text_str.encode("ISO-8859-1")
def base64Encode(self, inFile, outFile):
w = open(outFile, "w")
with open(inFile, "rb") as f:
byte = f.read(57)
while byte:
w.write(self.Encode(byte))
w.write("\n")
byte = f.read(57)
w.close()
f.close()
def base64Decode(self, inFile, outFile):
## Get size of input file for later comparison
fsize = os.path.getsize(inFile)
incsize = 0
eof = False
w = open(outFile, "wb")
with open(inFile, "r") as f:
byte = f.read(77)
while byte:
## keep current dataread and if current data read ==
## input file size set eof True
incsize += len(byte)
if fsize - incsize == 0:
eof = True
## Pass in eof to Decode
w.write(base64.base64Decode(byte, eof))
byte = f.read(77)
w.close()
f.close()