add filepath check, minimal.py, tdm_reaper.pyx: write_all

README.md

@@ -267,7 +267,16 @@ for grp in grpids :
         print("failed to print channelgroup: " + str(grp) + " : " + str(e))
 ```
 
-For a full example including more details see `python/usage.py`.
+For a full example including more details see [python/usage.py](python/usage.py)
+and the absolute minimal example [minimal usage](python/minimal.py). In order
+to simply extract all data of the TDM datatset and dump it to files in a given
+(existing!) directory, do
+
+```Python
+import tdm_reaper
+jack = tdm_reaper.tdmreaper(b'samples/SineData.tdm',b'samples/SineData.tdx')
+jack.write_all(b"./my_tdm_data/")
+```
 
 ## References
 

cython/py_tdm_reaper.pyx

@@ -42,3 +42,10 @@ cdef class tdmreaper:
   def print_channel(self, string id, const char* filename,
                           bool include_meta):
     self.cpp_tdm.print_channel(id,filename,include_meta)
+
+  # print all data grouped by channelgroups
+  def write_all(self, string outputdir) :
+    grpids = self.cpp_tdm.get_channelgroup_ids()
+    for id in grpids :
+      grpfile = outputdir.decode() + "/channelgroup_" + id.decode() + ".csv"
+      self.cpp_tdm.print_group(id,grpfile.encode(),True,ord(','))

cython/tdm_reaper.pxd

@@ -24,5 +24,5 @@ cdef extern from "tdm_reaper.hpp":
     string get_channelgroup_info(string id) except+
     string get_channel_info(string id) except+
     # print a channel(-group)
-    void print_group(string id, const char* filename, bool include_meta, char delimiter)
-    void print_channel(string id, const char* filename, bool include_meta)
+    void print_group(string id, const char* filename, bool include_meta, char delimiter) except+
+    void print_channel(string id, const char* filename, bool include_meta) except+

lib/tdm_reaper.cpp

@@ -610,6 +610,9 @@ std::vector<tdmdatatype> tdm_reaper::get_channel(std::string& id)
 
 void tdm_reaper::print_channel(std::string &id, const char* filename, bool include_meta)
 {
+  // check required path
+  this->check_filename_path(filename);
+
   // check for channel id
   if ( this->tdmchannels_.count(id) != 1 )
   {
@@ -652,6 +655,9 @@ void tdm_reaper::print_channel(std::string &id, const char* filename, bool inclu
 
 void tdm_reaper::print_group(std::string &id, const char* filename, bool include_meta, char sep)
 {
+  // check required path
+  this->check_filename_path(filename);
+
   // check for group id
   if ( this->tdmchannelgroups_.count(id) != 1 )
   {
@@ -761,6 +767,20 @@ void tdm_reaper::print_group(std::string &id, const char* filename, bool include
   }
 }
 
+void tdm_reaper::check_filename_path(const char* filename)
+{
+  // declare filesystem path instance from filename
+  std::filesystem::path pt(filename);
+
+  // get pure directory path
+  pt.remove_filename();
+
+  if ( !std::filesystem::is_directory(pt) )
+  {
+    throw std::runtime_error(std::string("directory does not exist: ") + pt.c_str() );
+  }
+}
+
 // -------------------------------------------------------------------------- //
 
 void tdm_reaper::check_local_datatypes()

lib/tdm_reaper.hpp

@@ -208,6 +208,7 @@ public:
   // dump a single channel/entire group (identified by id) to file
   void print_channel(std::string &id, const char* filename, bool include_meta = true);
   void print_group(std::string &id, const char* filename, bool include_meta = true, char sep = ' ');
+  void check_filename_path(const char* filename);
 
   // check machine's datatypes
   // https://en.cppreference.com/w/cpp/language/types

python/minimal.py

@@ -0,0 +1,15 @@
+
+import tdm_reaper
+
+# create 'tdm_reaper' instance object
+try :
+    jack = tdm_reaper.tdmreaper(b'samples/SineData.tdm',b'samples/SineData.tdx')
+    # list ids of channelgroups
+    grpids = jack.get_channelgroup_ids()
+    # iterate through groups
+    for grp in grpids :
+        # write channelgroup to file (prepend './' for local directory!!)
+        grpfile = "./channelgroup_" + str(grp.decode()) + ".csv"
+        jack.print_channelgroup(grp,grpfile.encode(),True,ord(' '))
+except RuntimeError as e :
+    print("failed to load/decode/write TDM files: " + str(e))

src/main.cpp

@@ -391,7 +391,7 @@ int main(int argc, char* argv[])
     }
   }
 
-  //std::this_thread::sleep_for(std::chrono::milliseconds(10000));
+  // std::this_thread::sleep_for(std::chrono::milliseconds(10000));
 
   return 0;
 }