diff --git a/lib/tdm_ripper.hpp b/lib/tdm_ripper.hpp
index b8152d3..0443bfa 100644
--- a/lib/tdm_ripper.hpp
+++ b/lib/tdm_ripper.hpp
@@ -203,6 +203,21 @@ public:
     return units_[obtain_channel_id(groupid,channelid)-1];
   }
 
+  int channel_exists(int groupid, std::string channel_name)
+  {
+    assert( groupid > 0 && groupid <= num_channels_ );
+
+    int channelid = 0;
+    for ( int i = 0; i < num_channels_group_[groupid-1]; i++)
+    {
+      if ( channel_name_[obtain_channel_id(groupid,i+1)-1].compare(channel_name) == 0 )
+      {
+        channelid = i+1;
+      }
+    }
+    return channelid;
+  }
+
   void list_datatypes();
 
   // convert array of chars to single integer or floating point double
diff --git a/pytdm_ripper.pyx b/pytdm_ripper.pyx
index e7ebb18..d1e4738 100644
--- a/pytdm_ripper.pyx
+++ b/pytdm_ripper.pyx
@@ -16,6 +16,9 @@ cdef class pytdmripper:
     def show_channels(self):
         self.cripp.list_channels()
 
+    def show_groups(self):
+      self.cripp.list_groups()
+
     def num_channels(self):
         return self.cripp.num_channels()
 
@@ -35,6 +38,9 @@ cdef class pytdmripper:
     def channel_unit(self,int groupid,int channelid):
         return (self.cripp.channel_unit(groupid+1,channelid+1))
 
+    def channel_exists(self,int groupid, string channelname):
+        return self.cripp.channel_exists(groupid+1,channelname)
+
     def get_channel(self, int channelid):
         return np.asarray(self.cripp.get_channel(channelid))
 
diff --git a/tdm_ripper.pxd b/tdm_ripper.pxd
index 3e57732..5d1386a 100644
--- a/tdm_ripper.pxd
+++ b/tdm_ripper.pxd
@@ -12,12 +12,14 @@ cdef extern from "tdm_ripper.hpp":
     cdef cppclass tdm_ripper:
         tdm_ripper(string) except +
         void list_channels()
+        void list_groups()
         int num_channels()
         int no_channels(int)
         int num_groups()
         int no_channel_groups()
         string channel_name(int,int)
         string channel_unit(int,int)
+        int channel_exists(int,string)
         vector[double] get_channel(int)
         vector[double] channel(int,int)
         void print_channel(int,const char*)