d = { 'foo' : 'bar',
'ev123' : 'found it!',
'baz' : 'qux' }
result = [v for k, v in d.iteritems() if k.startswith('ev')][0]
print result
ZCA9IHsgJ2ZvbycgOiAnYmFyJywKICAgICAgJ2V2MTIzJyA6ICdmb3VuZCBpdCEnLAogICAgICAnYmF6JyA6ICdxdXgnIH0KICAgICAgCnJlc3VsdCA9IFt2IGZvciBrLCB2IGluIGQuaXRlcml0ZW1zKCkgaWYgay5zdGFydHN3aXRoKCdldicpXVswXQoKcHJpbnQgcmVzdWx0