Improve Embedded Python Support

Discussion:
https://groups.google.com/d/msg/ledger-cli/kq9sKoRX9vw/fmyhvPslzokJ

src/py_account.cc

@@ -35,6 +35,7 @@
 #include "pyutils.h"
 #include "account.h"
 #include "post.h"
+#include "expr.h"
 
 namespace ledger {
 
@@ -97,6 +98,26 @@ namespace {
     return str_to_py_unicode(account.fullname());
   }
 
+  value_t py_amount_0(const account_t& account)
+  {
+      return account.amount();
+  }
+
+  value_t py_amount_1(const account_t& account, const boost::optional<expr_t&>& expr)
+  {
+      return account.amount(expr);
+  }
+
+  value_t py_total_0(const account_t& account)
+  {
+      return account.total();
+  }
+
+  value_t py_total_1(const account_t& account, const boost::optional<expr_t&>& expr)
+  {
+      return account.total(expr);
+  }
+
 } // unnamed namespace
 
 void export_account()
@@ -221,8 +242,10 @@ void export_account()
     .def("xdata", py_xdata,
          return_internal_reference<>())
 
-    .def("amount", &account_t::amount)
-    .def("total", &account_t::total)
+    .def("amount", py_amount_0)
+    .def("amount", py_amount_1, args("expr"))
+    .def("total", py_total_0)
+    .def("total", py_total_1, args("expr"))
 
     .def("self_details", &account_t::self_details,
          return_internal_reference<>())

src/py_balance.cc

@@ -64,7 +64,7 @@ namespace {
 
   boost::optional<amount_t>
   py_commodity_amount_1(const balance_t& balance,
-                        const boost::optional<const commodity_t&>& commodity) {
+                        const commodity_t& commodity) {
     return balance.commodity_amount(commodity);
   }
 

src/py_session.cc

@@ -61,6 +61,8 @@ void export_session()
     .def("read_journal_files", &session_t::read_journal_files,
          return_internal_reference<>())
     .def("close_journal_files", &session_t::close_journal_files)
+    .def("journal", &session_t::get_journal,
+         return_internal_reference<>())
     ;
 
   scope().attr("session") =

src/session.cc

@@ -265,6 +265,11 @@ void session_t::close_journal_files()
   amount_t::initialize();
 }
 
+journal_t * session_t::get_journal()
+{
+    return journal.get();
+}
+
 value_t session_t::fn_account(call_scope_t& args)
 {
   if (args[0].is_string())

src/session.h

@@ -84,6 +84,8 @@ public:
   journal_t * read_journal_files();
   void close_journal_files();
 
+  journal_t * get_journal();
+
   value_t fn_account(call_scope_t& scope);
   value_t fn_min(call_scope_t& scope);
   value_t fn_max(call_scope_t& scope);