Поскольку error codes отличаются от платформы и языка пользователя может отличаться, это обычно лучше всего печатать исключение в обычном режиме.
Однако, если вы действительно хотите список:
import os
import errno
print {i:os.strerror(i) for i in sorted(errno.errorcode)}
распечаток (на OS X):
{1: 'Operation not permitted', 2: 'No such file or directory', 3: 'No such process', 4: 'Interrupted system call', 5: 'Input/output error', 6: 'Device not configured', 7: 'Argument list too long', 8: 'Exec format error', 9: 'Bad file descriptor', 10: 'No child processes', 11: 'Resource deadlock avoided', 12: 'Cannot allocate memory', 13: 'Permission denied', 14: 'Bad address', 15: 'Block device required', 16: 'Resource busy', 17: 'File exists', 18: 'Cross-device link', 19: 'Operation not supported by device', 20: 'Not a directory', 21: 'Is a directory', 22: 'Invalid argument', 23: 'Too many open files in system', 24: 'Too many open files', 25: 'Inappropriate ioctl for device', 26: 'Text file busy', 27: 'File too large', 28: 'No space left on device', 29: 'Illegal seek', 30: 'Read-only file system', 31: 'Too many links', 32: 'Broken pipe', 33: 'Numerical argument out of domain', 34: 'Result too large', 35: 'Resource temporarily unavailable', 36: 'Operation now in progress', 37: 'Operation already in progress', 38: 'Socket operation on non-socket', 39: 'Destination address required', 40: 'Message too long', 41: 'Protocol wrong type for socket', 42: 'Protocol not available', 43: 'Protocol not supported', 44: 'Socket type not supported', 46: 'Protocol family not supported', 47: 'Address family not supported by protocol family', 48: 'Address already in use', 49: "Can't assign requested address", 50: 'Network is down', 51: 'Network is unreachable', 52: 'Network dropped connection on reset', 53: 'Software caused connection abort', 54: 'Connection reset by peer', 55: 'No buffer space available', 56: 'Socket is already connected', 57: 'Socket is not connected', 58: "Can't send after socket shutdown", 59: "Too many references: can't splice", 60: 'Operation timed out', 61: 'Connection refused', 62: 'Too many levels of symbolic links', 63: 'File name too long', 64: 'Host is down', 65: 'No route to host', 66: 'Directory not empty', 68: 'Too many users', 69: 'Disc quota exceeded', 70: 'Stale NFS file handle', 71: 'Too many levels of remote in path', 77: 'No locks available', 78: 'Function not implemented', 84: 'Value too large to be stored in data type', 90: 'Identifier removed', 91: 'No message of desired type', 92: 'Illegal byte sequence', 94: 'Bad message', 95: 'EMULTIHOP (Reserved)', 96: 'No message available on STREAM', 97: 'ENOLINK (Reserved)', 98: 'No STREAM resources', 99: 'Not a STREAM', 100: 'Protocol error', 101: 'STREAM ioctl timeout', 102: 'Operation not supported on socket'}
http://hg.python.org/cpython/file/ca9a85c36e09/Include /errcode.h –