Remove string module use from external modules.

IPython/external/Itpl.py

@@ -75,7 +75,6 b' each time the instance is evaluated with str(instance). For example:'
 __author__  = 'Ka-Ping Yee <[e-mail]>'
 __license__ = 'MIT'
 
-import string
 import sys
 from tokenize import tokenprog
 

IPython/external/pexpect.py

@@ -66,7 +66,6 b' $Id: pexpect.py 507 2007-12-27 02:40:52Z noah $'
 try:
     import os, sys, time
     import select
-    import string
     import re
     import struct
     import resource
@@ -1778,8 +1777,7 b' def which (filename):'
 
     # Oddly enough this was the one line that made Pexpect
     # incompatible with Python 1.5.2.
-    #pathlist = p.split (os.pathsep)
-    pathlist = string.split (p, os.pathsep)
+    pathlist = p.split(os.pathsep)
 
     for path in pathlist:
         f = os.path.join(path, filename)