blocks|key|1236355|text|在解码之前，你似乎只需要在你的字节中添加填充。关于这个问题还有很多其他的答案，但我想指出的是(至少在Python3.x中)+base64.b64decode将截断任何额外的填充，前提是首先有足够的填充。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1236356|所以，像这样的东西：b'abc='和b'abc=='一样好(b'abc====='也一样)。|1236357|这意味着您只需添加所需的最大填充字符数-即两个(b'==')-and+base64将截断任何不必要的字符。|1236358|这可以让你写下：|1236359|base64.b64decode(s+%2B+b'==')|code-block|syntax|javascript|1236360|这比以下内容简单：|1236361|base64.b64decode(s+%2B+b'='+*+(-len(s)+%25+4))|1236362|entityMap^0|1Q|G|0|A|7|I|8|U|B|0|O|5|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|Z|8|@$9|10|A|11|B|C]|$9|12|A|13|B|C]|$9|14|A|15|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|16|8|@$9|17|A|18|B|C]]|D|@]|E|$]]|$1|J|3|K|5|6|7|19|8|@]|D|@]|E|$]]|$1|L|3|M|5|N|7|1A|8|@]|D|@]|E|$O|P]]|$1|Q|3|R|5|6|7|1B|8|@]|D|@]|E|$]]|$1|S|3|T|5|N|7|1C|8|@]|D|@]|E|$O|P]]|$1|U|3|-4|5|6|7|1D|8|@]|D|@]|E|$]]]|V|$]]

It seems you just need to add padding to your bytes before decoding. There are many other answers on this question, but I want to point out that (at least in Python 3.x) <code>base64.b64decode</code> will truncate any extra padding, provided there is enough in the first place.
So, something like: <code>b'abc='</code> works just as well as <code>b'abc=='</code> (as does <code>b'abc====='</code>).
What this means is that you can just add the maximum number of padding characters that you would ever need—which is two (<code>b'=='</code>)—and base64 will truncate any unnecessary ones.
This lets you write:
<pre class="lang-py prettyprint-override"><code>base64.b64decode(s + b'==')
</code></pre>
which is simpler than:
<pre class="lang-py prettyprint-override"><code>base64.b64decode(s + b'=' * (-len(s) % 4))
</code></pre>

blocks|key|1236009|text|只需根据需要添加填充即可。不过，还是听从了迈克尔的警告。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1236010|b64_string+%2B=+"="+*+((4+-+len(b64_string)+%25+4)+%25+4)+#ugh|code-block|syntax|javascript|1236011|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Just add padding as required. Heed Michael's warning, however.

<pre><code>b64_string += "=" * ((4 - len(b64_string) % 4) % 4) #ugh
</code></pre>

blocks|key|1236100|text|使用|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1236101|string+%2B=+'='+*+(-len(string)+%25+4)++#+restore+stripped+'='s|code-block|syntax|javascript|1236102|功劳归功于这里的某处评论。|1236103|>>>+import+base64

>>>+enc+=+base64.b64encode('1')

>>>+enc
>>>+'MQ=='

>>>+base64.b64decode(enc)
>>>+'1'

>>>+enc+=+enc.rstrip('=')

>>>+enc
>>>+'MQ'

>>>+base64.b64decode(enc)
...
TypeError:+Incorrect+padding

>>>+base64.b64decode(enc+%2B+'='+*+(-len(enc)+%25+4))
>>>+'1'

>>>+|1236104|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Use 

<pre><code>string += '=' * (-len(string) % 4) # restore stripped '='s
</code></pre>

Credit goes to a comment somewhere here.

<pre><code>&gt;&gt;&gt; import base64

&gt;&gt;&gt; enc = base64.b64encode('1')

&gt;&gt;&gt; enc
&gt;&gt;&gt; 'MQ=='

&gt;&gt;&gt; base64.b64decode(enc)
&gt;&gt;&gt; '1'

&gt;&gt;&gt; enc = enc.rstrip('=')

&gt;&gt;&gt; enc
&gt;&gt;&gt; 'MQ'

&gt;&gt;&gt; base64.b64decode(enc)
...
TypeError: Incorrect padding

&gt;&gt;&gt; base64.b64decode(enc + '=' * (-len(enc) % 4))
&gt;&gt;&gt; '1'

&gt;&gt;&gt; 
</code></pre>

blocks|key|1235991|text|如果出现填充错误，可能意味着字符串已损坏；base64编码的字符串的长度应该是4的倍数。您可以尝试自己添加填充字符(=)，使字符串成为4的倍数，但除非出现错误，否则它应该已经有了填充字符|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1235992|entityMap^0|1M|1|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

If there's a padding error it probably means your string is corrupted; base64-encoded strings should have a multiple of four length. You can try adding the padding character (<code>=</code>) yourself to make the string a multiple of four, but it should already have that unless something is wrong

blocks|key|1236536|text|导致错误填充错误的原因是，有时，如果字符串看起来像这样：'data:image/png;base64，...base+64+stuff...‘，元数据也会出现在编码字符串中。然后你需要在解码前去掉第一部分。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1236537|假设您有图像base64编码的字符串，然后尝试下面的代码片段..|1236538|from+PIL+import+Image
from+io+import+BytesIO
from+base64+import+b64decode
imagestr+=+'data:image/png;base64,...base+64+stuff....'
im+=+Image.open(BytesIO(b64decode(imagestr.split(',')[1])))
im.save("image.png")|code-block|syntax|javascript|1236539|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|L|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|M|8|@]|9|@]|A|$G|H]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Incorrect padding error is caused because sometimes, metadata is also present in the encoded string
If your string looks something like: 'data:image/png;base64,...base 64 stuff....'
then you need to remove the first part before decoding it.

Say if you have image base64 encoded string, then try below snippet..

<pre><code>from PIL import Image
from io import BytesIO
from base64 import b64decode
imagestr = 'data:image/png;base64,...base 64 stuff....'
im = Image.open(BytesIO(b64decode(imagestr.split(',')[1])))
im.save("image.png")
</code></pre>

blocks|key|1021803|text|如果您正在尝试解码web图像，则可以简单地使用base64.urlsafe_b64decode(data)。它将自动处理填充。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1021804|entityMap^0|N|U|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|K|8|@]|D|@]|E|$]]]|G|$]]

You can simply use <code>base64.urlsafe_b64decode(data)</code> if you are trying to decode a web image. It will automatically take care of the padding.

blocks|key|1236153|text|添加填充是相当..。很麻烦。这是我在此线程中的评论以及base64+(出人意料地有用)+https://en.wikipedia.org/wiki/Base64#Padding的维基页面的帮助下编写的函数。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1236154|import+logging
import+base64
def+base64_decode(s):
++++"""Add+missing+padding+to+string+and+return+the+decoded+base64+string."""
++++log+=+logging.getLogger()
++++s+=+str(s).strip()
++++try:
++++++++return+base64.b64decode(s)
++++except+TypeError:
++++++++padding+=+len(s)+%25+4
++++++++if+padding+==+1:
++++++++++++log.error("Invalid+base64+string:+{}".format(s))
++++++++++++return+''
++++++++elif+padding+==+2:
++++++++++++s+%2B=+b'=='
++++++++elif+padding+==+3:
++++++++++++s+%2B=+b'='
++++++++return+base64.b64decode(s)|code-block|syntax|javascript|1236155|entityMap|0|LINK|mutability|MUTABLE|url|https://en.wikipedia.org/wiki/Base64#Padding^0|18|18|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@$A|R|B|S|1|T]]|C|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|V|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]]]

Adding the padding is rather... fiddly. Here's the function I wrote with the help of the comments in this thread as well as the wiki page for base64 (it's surprisingly helpful) <a href="https://en.wikipedia.org/wiki/Base64#Padding" rel="nofollow">https://en.wikipedia.org/wiki/Base64#Padding</a>.

<pre><code>import logging
import base64
def base64_decode(s):
 """Add missing padding to string and return the decoded base64 string."""
 log = logging.getLogger()
 s = str(s).strip()
 try:
 return base64.b64decode(s)
 except TypeError:
 padding = len(s) % 4
 if padding == 1:
 log.error("Invalid base64 string: {}".format(s))
 return ''
 elif padding == 2:
 s += b'=='
 elif padding == 3:
 s += b'='
 return base64.b64decode(s)
</code></pre>

blocks|key|1236201|text|如果此错误来自web服务器:尝试使用url编码您的帖子值。我通过"curl“解码，发现我没有对我的base64值进行url编码，所以像"%2B”这样的字符不会被转义，所以web服务器的url解码逻辑会自动运行url解码并将%2B转换为空格。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1236202|"%2B“是一个有效的base64字符，并且可能是唯一被意外的url-decode损坏的字符。|1236203|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

In case this error came from a web server: Try url encoding your post value. I was POSTing via "curl" and discovered I wasn't url-encoding my base64 value so characters like "+" were not escaped so the web server url-decode logic automatically ran url-decode and converted + to spaces.

"+" is a valid base64 character and perhaps the only character which gets mangled by an unexpected url-decode.

blocks|key|1021659|text|你应该使用|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1021660|base64.b64decode(b64_string,+'+/')|code-block|syntax|javascript|1021661|默认情况下，altchars为'%2B/'。|offset|length|style|CODE|1021662|entityMap^0|0|0|F|4|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|Q|8|@$I|R|J|S|K|L]]|9|@]|A|$]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

You should use

<pre><code>base64.b64decode(b64_string, ' /')
</code></pre>

By default, the altchars are <code>'+/'</code>.

blocks|key|1236424|text|我也遇到了这个问题，但什么都不起作用。我终于找到了适合我的解决方案。我在base64中压缩了内容，这发生在每一百万条记录中就有一条……|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1236425|这是Simon+Sapin建议的解决方案的一个版本。|1236426|如果填充符缺少3个，那么我删除最后3个字符。|1236427|不是"0gA1RD5L/9AUGtH9MzAwAAA==“|1236428|我们得到"0gA1RD5L/9AUGtH9MzAwAA“|1236429|++++++++missing_padding+=+len(data)+%25+4
++++++++if+missing_padding+==+3:
++++++++++++data+=+data[0:-3]
++++++++elif+missing_padding+!=+0:
++++++++++++print+("Missing+padding+:+"+%2B+str(missing_padding))
++++++++++++data+%2B=+'='+*+(4+-+missing_padding)
++++++++data_decoded+=+base64.b64decode(data)+++|code-block|syntax|javascript|1236430|根据这个答案，Trailing+As+in+base64的原因是空值。但我还是不知道为什么编码器搞砸了.|offset|length|1236431|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/18221065/tar-co-base64-output-contains-several-hundred-bytes-of-aaa-at-the-end^0|0|0|0|0|0|0|7|L|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|11|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|12|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|13|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|14|8|@]|9|@]|A|$]]|$1|J|3|K|5|L|7|15|8|@]|9|@]|A|$M|N]]|$1|O|3|P|5|6|7|16|8|@]|9|@$Q|17|R|18|1|19]]|A|$]]|$1|S|3|-4|5|6|7|1A|8|@]|9|@]|A|$]]]|T|$U|$5|V|W|X|A|$Y|Z]]]]

I ran into this problem as well and nothing worked.
I finally managed to find the solution which works for me. I had zipped content in base64 and this happened to 1 out of a million records...

This is a version of the solution suggested by Simon Sapin.

In case the padding is missing 3 then I remove the last 3 characters.

Instead of "0gA1RD5L/9AUGtH9MzAwAAA=="

We get "0gA1RD5L/9AUGtH9MzAwAA"

<pre><code> missing_padding = len(data) % 4
 if missing_padding == 3:
 data = data[0:-3]
 elif missing_padding != 0:
 print ("Missing padding : " + str(missing_padding))
 data += '=' * (4 - missing_padding)
 data_decoded = base64.b64decode(data) 
</code></pre>

According to this answer <a href="https://stackoverflow.com/questions/18221065/tar-co-base64-output-contains-several-hundred-bytes-of-aaa-at-the-end">Trailing As in base64</a> the reason is nulls. But I still have no idea why the encoder messes this up...

blocks|key|1236674|text|在我的例子中，Gmail+Web+API以base64编码字符串的形式返回电子邮件内容，但是没有使用标准的base64字符/字母表进行编码，而是使用base64的“web安全”字符/字母表变体进行编码。%2B和/字符将替换为-和_。对于Python3，使用base64.urlsafe_b64decode()。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1236675|entityMap^0|2T|1|2V|1|32|1|34|1|3I|Q|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]|$9|M|A|N|B|C]|$9|O|A|P|B|C]|$9|Q|A|R|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|G|$]]

In my case Gmail Web API was returning the email content as a base64 encoded string, but instead of encoded with the standard base64 characters/alphabet, it was encoded with the &quot;web-safe&quot; characters/alphabet variant of base64. The <code>+</code> and <code>/</code> characters are replaced with <code>-</code> and <code>_</code>. For python 3 use <code>base64.urlsafe_b64decode()</code>.

blocks|key|1022031|text|清除您的浏览器cookie，并再次检查，它应该可以工作。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1022032|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Clear your browser cookie and recheck again, it should work.

blocks|key|1236731|text|def+base64_decode(data:+str)+->+str:
++++
++++data+=+data.encode("ascii")

++++rem+=+len(data)+%25+4

++++if+rem+>+0:
++++++++data+%2B=+b"="+*+(4+-+rem)
++++return+base64.urlsafe_b64decode(data).decode('utf-8')|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1236732|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre class="lang-py prettyprint-override"><code>def base64_decode(data: str) -&gt; str:
 
 data = data.encode(&quot;ascii&quot;)

 rem = len(data) % 4

 if rem &gt; 0:
 data += b&quot;=&quot; * (4 - rem)
 return base64.urlsafe_b64decode(data).decode('utf-8')
</code></pre>

blocks|key|1021445|text|在尝试解码目标字符串值之前，只需添加额外的字符，如"=“或任何其他字符，并使其成为4的倍数。就像这样；|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1021446|if+len(value)+%25+4+!=+0:+#check+if+multiple+of+4
++++while+len(value)+%25+4+!=+0:
++++++++value+=+value+%2B+"="
++++req_str+=+base64.b64decode(value)
else:
++++req_str+=+base64.b64decode(value)|code-block|syntax|javascript|1021447|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Simply add additional characters like "=" or any other and make it a multiple of 4 before you try decoding the target string value. Something like;

<pre><code>if len(value) % 4 != 0: #check if multiple of 4
 while len(value) % 4 != 0:
 value = value + "="
 req_str = base64.b64decode(value)
else:
 req_str = base64.b64decode(value)
</code></pre>

blocks|key|1236239|text|在我的例子中，我在解析电子邮件时遇到了这个错误。我获得了base64字符串形式的附件，并通过re.search将其提取出来。最后，在末尾有一个奇怪的附加子字符串。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1236240|dHJhaWxlcgo8PCAvU2l6ZSAxNSAvUm9vdCAxIDAgUiAvSW5mbyAyIDAgUgovSUQgWyhcMDAyXDMz
MHtPcFwyNTZbezU/VzheXDM0MXFcMzExKShcMDAyXDMzMHtPcFwyNTZbezU/VzheXDM0MXFcMzEx
KV0KPj4Kc3RhcnR4cmVmCjY3MDEKJSVFT0YK

--_=ic0008m4wtZ4TqBFd%2BsXC8--|code-block|syntax|javascript|1236241|当我删除了--_=ic0008m4wtZ4TqBFd%2BsXC8--并剥离了字符串之后，解析就被修复了。|offset|length|style|CODE|1236242|所以我的建议是确保你解码的是一个正确的base64字符串。|1236243|entityMap^0|0|0|5|S|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@$I|T|J|U|K|L]]|9|@]|A|$]]|$1|M|3|N|5|6|7|V|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

In my case I faced that error while parsing an email. I got the attachment as base64 string and extract it via re.search. Eventually there was a strange additional substring at the end.

<pre><code>dHJhaWxlcgo8PCAvU2l6ZSAxNSAvUm9vdCAxIDAgUiAvSW5mbyAyIDAgUgovSUQgWyhcMDAyXDMz
MHtPcFwyNTZbezU/VzheXDM0MXFcMzExKShcMDAyXDMzMHtPcFwyNTZbezU/VzheXDM0MXFcMzEx
KV0KPj4Kc3RhcnR4cmVmCjY3MDEKJSVFT0YK

--_=ic0008m4wtZ4TqBFd+sXC8--
</code></pre>

When I deleted <code>--_=ic0008m4wtZ4TqBFd+sXC8--</code> and strip the string then parsing was fixed up. 

So my advise is make sure that you are decoding a correct base64 string.

blocks|key|1236621|text|在我的例子中，在删除perticular项目的venv之后，我遇到了这个错误，它显示了每个字段的错误，所以我尝试通过更改浏览器(Chrome+to+Edge)，实际上它起作用了。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1236622|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

In my case I faced this error, after deleting the venv for the perticular project and it showing error for each fields so I tried by changing the BROWSER(Chrome to Edge), And actually it worked..

I have some data that is base64 encoded that I want to convert back to binary even if there is a padding error in it. If I use 

<pre><code>base64.decodestring(b64_string)
</code></pre>

it raises an 'Incorrect padding' error. Is there another way?

UPDATE: Thanks for all the feedback. To be honest, all the methods mentioned sounded a bit hit
and miss so I decided to try openssl. The following command worked a treat:

<pre><code>openssl enc -d -base64 -in b64string -out binary_data
</code></pre>

Python: Ignore 'Incorrect padding' error when base64 decoding

我有一些base64编码的数据，我想转换回二进制，即使其中有填充错误。如果我使用base64.decodestring(b64_string)它会引发“不正确的填充”错误。还有别的办法吗？更新:感谢所有的反馈。老实说，上面提到的所有方法听起来都不太靠谱，所以我决定尝试一下openssl。以下命令很管用：openssl enc -d -base64 -in b64string -out binary

问Python:在base64解码时忽略“不正确的填充”错误
EN

回答 16

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问Python:在base64解码时忽略“不正确的填充”错误EN

回答 16

Stack Overflow用户

Stack Overflow用户

Stack Overflow用户

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问Python:在base64解码时忽略“不正确的填充”错误
EN