Python2.7 help("modules")时出错（CentOS 64bits）

在虚拟机上运行时出现这个错误，查了下貌似没见到类似的情况。

使用版本是python2.7.5，升级到2.7.9后问题就没了

help> modules

Please wait a moment while I gather a list of all available modules...

BaseHTTPServer      array               imaplib             sgmllib
Bastion             ast                 imghdr              sha
CDROM               asynchat            imp                 shelve
CGIHTTPServer       asyncore            importlib           shlex
Canvas              atexit              imputil             shutil
ConfigParser        audiodev            inspect             signal
Cookie              audioop             io                  site
DLFCN               base64              itertools           smtpd
Dialog              bdb                 json                smtplib
DocXMLRPCServer     binascii            keyword             sndhdr
FileDialog          binhex              lib2to3             socket
FixTk               bisect              linecache           spwd
HTMLParser          bsddb               linuxaudiodev       sqlite3
IN                  cPickle             locale              sre
MimeWriter          cProfile            logging             sre_compile
Queue               cStringIO           macpath             sre_constants
ScrolledText        calendar            macurl2path         sre_parse
SimpleDialog        cgi                 mailbox             ssl
SimpleHTTPServer    cgitb               mailcap             stat
SimpleXMLRPCServer  chunk               markupbase          statvfs
SocketServer        cmath               marshal             string
StringIO            cmd                 math                stringold
TYPES               code                md5                 stringprep
Tix                 codecs              mhlib               strop
Tkconstants         codeop              mimetools           struct
Tkdnd               collections         mimetypes           subprocess
Tkinter             colorsys            mimify              sunau
UserDict            commands            mmap                sunaudio
UserList            compileall          modulefinder        symbol
UserString          compiler            multifile           symtable
_LWPCookieJar       contextlib          multiprocessing     sys
_MozillaCookieJar   cookielib           mutex               sysconfig
__builtin__         copy                netrc               syslog
__future__          copy_reg            new                 tabnanny
_abcoll             crypt               nis                 tarfile
_ast                csv                 nntplib             telnetlib
_bisect             ctypes              ntpath              tempfile
_codecs             curses              nturl2path          termios
_codecs_cn          datetime            numbers             test
_codecs_hk          dbhash              opcode              textwrap
_codecs_iso2022     decimal             operator            this
_codecs_jp          difflib             optparse            thread
_codecs_kr          dircache            os                  threading
_codecs_tw          dis                 os2emxpath          time
_collections        distutils           ossaudiodev         timeit
_csv                doctest             parser              tkColorChooser
_ctypes             dumbdbm             pdb                 tkCommonDialog
_ctypes_test        dummy_thread        pickle              tkFileDialog
_elementtree        dummy_threading     pickletools         tkFont
_functools          email               pipes               tkMessageBox
_heapq              encodings           pkgutil             tkSimpleDialog
_hotshot            ensurepip           platform            toaiff
_io                 errno               plistlib            token
_json               exceptions          popen2              tokenize
_locale             fcntl               poplib              trace
_lsprof             filecmp             posix               traceback
_md5                fileinput           posixfile           ttk
_multibytecodec     fnmatch             posixpath           tty
_multiprocessing    formatter           pprint              turtle
_osx_support        fpformat            profile             types
_pyio               fractions           pstats              unicodedata
_random             ftplib              pty                 unittest
_sha                functools           pwd                 urllib
_sha256             future_builtins     py_compile          urllib2
_sha512             gc                  pyclbr              urlparse
_socket             genericpath         pydoc               user
_sre                getopt              pydoc_data          uu
_strptime           getpass             pyexpat             uuid
_struct             gettext             quopri              warnings
_symtable           glob                random              wave
_sysconfigdata      grp                 re                  weakref
_testcapi           gzip                repr                webbrowser
_threading_local    hashlib             resource            whichdb
_warnings           heapq               rexec               wsgiref
_weakref            hmac                rfc822              xdrlib
_weakrefset         hotshot             rlcompleter         xml
abc                 htmlentitydefs      robotparser         xmllib
aifc                htmllib             runpy               xmlrpclib
antigravity         httplib             sched               xxsubtype
anydbm              idlelib             select              zipfile
argparse            ihooks              sets                zipimport

Enter any module name to get more help.  Or, type "modules spam" to search
for modules whose descriptions contain the word "spam".