pyDes | pure python module which implements the DES and Triple-DES | Encryption library

There are a lot of differences between both codes:

• In the Java code the key is generated by concatenating the 16 bytes MD5 hash with the first 8 bytes of the same hash. In the Python code, key generation does not seem to work at all (changing from {: <24} to [:24] does not really make it better). The 2nd change finally, digested_passkey[:24], is identical to digested_passkey and works because PyCryptodome automatically extends the key to 24 bytes according to 2-key Triple DES.
• In the Python code, two libraries are used: pyDes and PyCryptodome. Only one library should be applied here. Regarding PyCryptodome AES is used. Actually AES is the faster/modern algorithm compared to Triple DES, but it just differs from that of the Java code.
• The Python code also implements padding, which is not necessary, because PyCryptodome (in contrast to the legacy PyCrypto) supports padding. Apart from that the padding is wrongly implemented because it uses a block size of 16 bytes, but Triple DES has a block size of 8 bytes.
• In the Java code a 0 vector is taken for the IV, in the Python code a random IV (which is actually correct, but just differs from the Java code).
• In the Java code IV and ciphertext are not concatenated, in the Python code they are concatenated (which is actually correct, but just differs from the Java code).

Apart from that, the algorithms used are insecure (MD5) or outdated/slow (Triple DES), as already mentioned in the comment. Also a 0-vector as IV is completely insecure.

Based on the equals padding, I strongly suspect your IV is base64 encoded. Perhaps the original API expected to receive it base64 encoded? If you do base64.b64decode("AStringOfIV=") it produces a length 8 IV, b'\x01+k\x8ax\x0e|\x85', which may get the behavior you want.