Add support for print to file and file flush.

Author: raff

builtin/builtin.go

@@ -6,7 +6,6 @@
 package builtin
 
 import (
-"fmt"
 "unicode/utf8"
 
 "github.com/go-python/gpython/compile"
@@ -177,7 +176,7 @@ func builtin_print(self py.Object, args py.Tuple, kwargs py.StringDict) (py.Obje
 var (
 sepObj py.Object=py.String(" ")
 endObj py.Object=py.String("\n")
-file py.Object
+file py.Object=py.MustGetModule("sys").Globals["stdout"]
 flush py.Object
  )
 kwlist:= []string{"sep", "end", "file", "flush"}
@@ -187,19 +186,43 @@ func builtin_print(self py.Object, args py.Tuple, kwargs py.StringDict) (py.Obje
  }
 sep:=sepObj.(py.String)
 end:=endObj.(py.String)
-// FIXME ignoring file and flush
+
+write, err:=py.GetAttrString(file, "write")
+iferr!=nil{
+returnnil, err
+ }
+
 fori, v:=rangeargs{
 v, err:=py.Str(v)
 iferr!=nil{
 returnnil, err
  }
 
-fmt.Printf("%v", v)
+_, err=py.Call(write, py.Tuple{v}, nil)
+iferr!=nil{
+returnnil, err
+ }
+
 ifi!=len(args)-1{
-fmt.Print(sep)
+_, err=py.Call(write, py.Tuple{sep}, nil)
+iferr!=nil{
+returnnil, err
+ }
  }
  }
-fmt.Print(end)
+
+_, err=py.Call(write, py.Tuple{end}, nil)
+iferr!=nil{
+returnnil, err
+ }
+
+ifshouldFlush, _:=py.MakeBool(flush); shouldFlush==py.True{
+fflush, err:=py.GetAttrString(file, "flush")
+iferr==nil{
+py.Call(fflush, nil, nil)
+ }
+ }
+
 returnpy.None, nil
 }
 

builtin/tests/builtin.py

@@ -147,9 +147,42 @@ def gen2():
 assertrepr("hello") =="'hello'"
 
 doc="print"
-# FIXME - need io redirection to test
-#print("hello world")
-#print(1,2,3,sep=",",end=",\n")
+ok=False
+try:
+print("hello", sep=1)
+exceptTypeErrorase:
+#if e.args[0] != "sep must be None or a string, not int":
+# raise
+ok=True
+assertok, "TypeError not raised"
+
+try:
+print("hello", sep=" ", end=1)
+exceptTypeErrorase:
+#if e.args[0] != "end must be None or a string, not int":
+# raise
+ok=True
+assertok, "TypeError not raised"
+
+try:
+print("hello", sep=" ", end="\n", file=1)
+exceptAttributeErrorase:
+#if e.args[0] != "'int' object has no attribute 'write'":
+# raise
+ok=True
+assertok, "AttributeError not raised"
+
+withopen("testfile", "w") asf:
+print("hello", "world", sep=" ", end="\n", file=f)
+
+withopen("testfile", "r") asf:
+assertf.read() =="hello world\n"
+
+withopen("testfile", "w") asf:
+print(1,2,3,sep=",",end=",\n", file=f)
+
+withopen("testfile", "r") asf:
+assertf.read() =="1,2,3,\n"
 
 doc="round"
 assertround(1.1) ==1.0

py/file.go

@@ -16,6 +16,7 @@ import (
 )
 
 varFileType=NewType("file", `represents an open file`)
+varerrClosed=ExceptionNewf(ValueError, "I/O operation on closed file.")
 
 funcinit(){
 FileType.Dict["write"] =MustNewMethod("write", func(selfObject, valueObject) (Object, error){
@@ -28,6 +29,9 @@ func init(){
 FileType.Dict["close"] =MustNewMethod("close", func(selfObject) (Object, error){
 returnself.(*File).Close()
  }, 0, "close() -> None or (perhaps) an integer. Close the file.\n\nSets data attribute .closed to True. A closed file cannot be used for\nfurther I/O operations. close() may be called more than once without\nerror. Some kinds of file objects (for example, opened by popen())\nmay return an exit status upon closing.")
+FileType.Dict["flush"] =MustNewMethod("flush", func(selfObject) (Object, error){
+returnself.(*File).Flush()
+ }, 0, "flush() -> Flush the write buffers of the stream if applicable. This does nothing for read-only and non-blocking streams.")
 }
 
 typeFileModeint
@@ -71,6 +75,9 @@ func (o *File) Write(value Object) (Object, error){
  }
 
 n, err:=o.File.Write(b)
+iferr!=nil&&err.(*os.PathError).Err==os.ErrClosed{
+returnnil, errClosed
+ }
 returnInt(n), err
 }
 
@@ -123,10 +130,14 @@ func (o *File) Read(args Tuple, kwargs StringDict) (Object, error){
  }
 
 b, err:=ioutil.ReadAll(r)
-iferr==io.EOF{
-returno.readResult(nil)
- }
 iferr!=nil{
+iferr==io.EOF{
+returno.readResult(nil)
+ }
+ifperr, ok:=err.(*os.PathError); ok&&perr.Err==os.ErrClosed{
+returnnil, errClosed
+ }
+
 returnnil, err
  }
 
@@ -138,6 +149,24 @@ func (o *File) Close() (Object, error){
 returnNone, nil
 }
 
+func (o*File) Flush() (Object, error){
+err:=o.File.Sync()
+ifperr, ok:=err.(*os.PathError); ok&&perr.Err==os.ErrClosed{
+returnnil, errClosed
+ }
+
+returnNone, nil
+}
+
+func (o*File) M__enter__() (Object, error){
+returno, nil
+}
+
+func (o*File) M__exit__(exc_type, exc_value, tracebackObject) (Object, error){
+o.Close()
+returnNone, nil
+}
+
 funcOpenFile(filename, modestring, bufferingint) (Object, error){
 varfileModeFileMode
 vartruncatebool
@@ -177,8 +206,8 @@ func OpenFile(filename, mode string, buffering int) (Object, error){
 returnnil, ExceptionNewf(ValueError, "Must have exactly one of create/read/write/append mode and at most one plus")
  }
 
+truncate= (fileMode&FileWrite) !=0
 fileMode|=FileReadWrite
-truncate=false
 
 case'b':
 iffileMode&FileReadWrite==0{
@@ -250,3 +279,5 @@ func OpenFile(filename, mode string, buffering int) (Object, error){
 }
 
 // Check interface is satisfied
+var_I__enter__= (*File)(nil)
+var_I__exit__= (*File)(nil)

py/tests/file.py

@@ -35,9 +35,13 @@
 assertn==5
 
 doc="close"
-f.close()
+assertf.close() ==None
+
+assertRaises(ValueError, f.read, 1)
+assertRaises(ValueError, f.write, "")
+assertRaises(ValueError, f.flush)
 
 # closing a closed file should not throw an error
-f.close()
+assertf.close()==None
 
 doc="finished"

pytest/pytest.go

@@ -12,7 +12,6 @@ import (
 "testing"
 
  _ "github.com/go-python/gpython/builtin"
- _ "github.com/go-python/gpython/sys"
 "github.com/go-python/gpython/compile"
 "github.com/go-python/gpython/py"
  _ "github.com/go-python/gpython/sys"