ConfigParserでkeyの存在確認する

config.ini

[main]
aaaa = hogehoge
bbbb = fugafuga
cccc = mogumogu

config_test.py

# -*- coding:utf-8 -*-
import ConfigParser

inifile = ConfigParser.SafeConfigParser()
inifile.read("config.ini")

# 中身確認
print inifile.items("main")
print map(lambda x:x[0], inifile.items("main"))

# mapを使う
if "aaaa" in map(lambda x:x[0], inifile.items("main")):
  print "aaaa is defined !"
else:
  print "aaaa is NOT defined !"

if "dddd" in map(lambda x:x[0], inifile.items("main")):
  print "dddd is defined !"
else:
  print "dddd is NOT defined !"

# filterを使う コードが長くなるなぁ。。。
if len(filter(lambda x:x[0] == "aaaa", inifile.items("main"))) is not 0:
  print "aaaa is defined !"

result

[('aaaa', 'hogehoge'), ('bbbb', 'fugafuga'), ('cccc', 'mogumogu')]
['aaaa', 'bbbb', 'cccc']
aaaa is defined !
dddd is NOT defined !
aaaa is defined !