diff --git a/Lib/ConfigParser.py b/Lib/ConfigParser.py
index e12717dbf00..d32eae03298 100644
--- a/Lib/ConfigParser.py
+++ b/Lib/ConfigParser.py
@@ -554,7 +554,7 @@ class ConfigParser(RawConfigParser):
         depth = MAX_INTERPOLATION_DEPTH
         while depth:                    # Loop through this until it's done
             depth -= 1
-            if value.find("%(") != -1:
+            if "%(" in value:
                 try:
                     value = value % vars
                 except KeyError, e:
@@ -562,7 +562,7 @@ class ConfigParser(RawConfigParser):
                         option, section, rawval, e[0])
             else:
                 break
-        if value.find("%(") != -1:
+        if "%(" in value:
             raise InterpolationDepthError(option, section, rawval)
         return value
 
diff --git a/Lib/_strptime.py b/Lib/_strptime.py
index 361f52e2dd9..22455ae9934 100644
--- a/Lib/_strptime.py
+++ b/Lib/_strptime.py
@@ -250,7 +250,7 @@ class TimeRE(dict):
         format = regex_chars.sub(r"\\\1", format)
         whitespace_replacement = re_compile('\s+')
         format = whitespace_replacement.sub('\s*', format)
-        while format.find('%') != -1:
+        while '%' in format:
             directive_index = format.index('%')+1
             processed_format = "%s%s%s" % (processed_format,
                                            format[:directive_index-1],
diff --git a/Lib/gettext.py b/Lib/gettext.py
index ed9d3ea990e..920aa4642ab 100644
--- a/Lib/gettext.py
+++ b/Lib/gettext.py
@@ -289,7 +289,7 @@ class GNUTranslations(NullTranslations):
             # cause no problems since us-ascii should always be a subset of
             # the charset encoding.  We may want to fall back to 8-bit msgids
             # if the Unicode conversion fails.
-            if msg.find('\x00') >= 0:
+            if '\x00' in msg:
                 # Plural forms
                 msgid1, msgid2 = msg.split('\x00')
                 tmsg = tmsg.split('\x00')
diff --git a/Lib/httplib.py b/Lib/httplib.py
index a23caf5651c..40e78b0fafe 100644
--- a/Lib/httplib.py
+++ b/Lib/httplib.py
@@ -348,7 +348,7 @@ class HTTPResponse:
             # An HTTP/1.1 proxy is assumed to stay open unless
             # explicitly closed.
             conn = self.msg.getheader('connection')
-            if conn and conn.lower().find("close") >= 0:
+            if conn and "close" in conn.lower():
                 return True
             return False
 
@@ -361,7 +361,7 @@ class HTTPResponse:
 
         # Proxy-Connection is a netscape hack.
         pconn = self.msg.getheader('proxy-connection')
-        if pconn and pconn.lower().find("keep-alive") >= 0:
+        if pconn and "keep-alive" in pconn.lower():
             return False
 
         # otherwise, assume it will close
diff --git a/Lib/keyword.py b/Lib/keyword.py
index a0295e2139e..223a88a9dea 100755
--- a/Lib/keyword.py
+++ b/Lib/keyword.py
@@ -63,7 +63,7 @@ def main():
     while 1:
         line = fp.readline()
         if not line: break
-        if line.find('{1, "') > -1:
+        if '{1, "' in line:
             match = strprog.search(line)
             if match:
                 lines.append("        '" + match.group(1) + "',\n")
diff --git a/Lib/robotparser.py b/Lib/robotparser.py
index 6b23188f196..13d8ac2528c 100644
--- a/Lib/robotparser.py
+++ b/Lib/robotparser.py
@@ -214,7 +214,7 @@ class Entry:
                 # we have the catch-all agent
                 return True
             agent = agent.lower()
-            if useragent.find(agent) != -1:
+            if agent in useragent:
                 return True
         return False
 
diff --git a/Lib/webbrowser.py b/Lib/webbrowser.py
index cb9dbb36bd8..f8b41e537c4 100644
--- a/Lib/webbrowser.py
+++ b/Lib/webbrowser.py
@@ -22,7 +22,7 @@ def get(using=None):
     else:
         alternatives = _tryorder
     for browser in alternatives:
-        if browser.find('%s') > -1:
+        if '%s' in browser:
             # User gave us a command line, don't mess with it.
             return GenericBrowser(browser)
         else: