Text and JSON representations of jbpy objects

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## Added
+- `print()` method now supports the `file` argument
+- `as_json()` and `as_text()` methods
+
 
 ## [0.5.1] - 2025-12-17
 

jbpy/_jbpinfo.py

@@ -1,6 +1,4 @@
 import argparse
-import collections.abc
-import json
 import os
 import sys
 
@@ -12,39 +10,6 @@
     pass
 
 
-class _Encoder(json.JSONEncoder):
-    def __init__(self, *args, full_details=False, **kwargs):
-        super().__init__(*args, **kwargs)
-        self.full_details = full_details
-
-    def default(self, obj):
-        if isinstance(obj, collections.abc.Mapping):
-            return dict(obj)
-        if isinstance(obj, bytes):
-            return list(obj)
-        if isinstance(obj, jbpy.core.Field):
-            if self.full_details:
-                return {
-                    "size": obj.size,
-                    "offset": obj.get_offset(),
-                    "value": obj.value,
-                }
-            return obj.value
-        if isinstance(obj, jbpy.core.BinaryPlaceholder):
-            if self.full_details:
-                return {
-                    "size": obj.size,
-                    "offset": obj.get_offset(),
-                    "value": "__binary__",
-                }
-            return f"__binary__ ({obj.get_size()} bytes)"
-        if isinstance(obj, jbpy.core.SegmentList):
-            return list(obj)
-        if isinstance(obj, jbpy.core.TreSequence):
-            return list(obj)
-        return super().default(obj)
-
-
 def main(args=None):
     parser = argparse.ArgumentParser(description="Display JBP Header content")
     parser.add_argument("filename", help="Path to JBP file")
@@ -63,7 +28,7 @@ def main(args=None):
     try:
         if "json" in config.format:
             full_details = config.format == "json-full"
-            print(json.dumps(jbp, indent=2, cls=_Encoder, full_details=full_details))
+            print(jbp.as_json(full_details))
         else:
             jbp.print()
     except BrokenPipeError:

jbpy/core.py

@@ -17,6 +17,8 @@
 import copy
 import datetime
 import importlib.metadata
+import io
+import json
 import logging
 import os
 import re
@@ -506,7 +508,22 @@ def get_size(self) -> int:
         """Size of this component in bytes"""
         raise NotImplementedError()
 
-    def print(self) -> None:
+    def as_json(self, full: bool = False) -> str:
+        """Return a JSON representation of the component
+        Args
+        ----
+        full : bool
+            Include additional details such as offset and length
+        """
+        return json.dumps(self, indent=2, cls=_JsonEncoder, full_details=full)
+
+    def as_text(self) -> str:
+        """Return a text representation of the component"""
+        buf = io.StringIO()
+        self.print(file=buf)
+        return buf.getvalue()
+
+    def print(self, *, file=None) -> None:
         """Print information about the component to stdout"""
         raise NotImplementedError()
 
@@ -713,9 +730,10 @@ def _dump_impl(self, fd: BinaryFile_RW) -> int:
     def get_size(self) -> int:
         return self.size
 
-    def print(self) -> None:
+    def print(self, *, file=None) -> None:
         print(
-            f"{self.name:15}{self.size:11} @ {self.get_offset():11} {self.encoded_value!r}"
+            f"{self.name:15}{self.size:11} @ {self.get_offset():11} {self.encoded_value!r}",
+            file=file,
         )
 
 
@@ -755,8 +773,10 @@ def _dump_impl(self, fd: BinaryFile_RW) -> int:
     def get_size(self) -> int:
         return self.size
 
-    def print(self) -> None:
-        print(f"{self.name:15}{self.size:11} @ {self.get_offset():11} <Binary>")
+    def print(self, *, file=None) -> None:
+        print(
+            f"{self.name:15}{self.size:11} @ {self.get_offset():11} <Binary>", file=file
+        )
 
 
 class ComponentCollection(JbpIOComponent):
@@ -826,9 +846,9 @@ def get_offset_of(self, child_obj: JbpIOComponent) -> int:
         else:
             raise ValueError(f"Could not find {child_obj.name}")
 
-    def print(self) -> None:
+    def print(self, *, file=None) -> None:
         for child in self._children:
-            child.print()
+            child.print(file=file)
 
     def finalize(self):
         for child in self._children:
@@ -894,10 +914,6 @@ def _remove_all(self, pattern: str) -> None:
     def _index(self, name: str) -> int:
         return self._child_names().index(name)
 
-    def print(self) -> None:
-        for child in self._children:
-            child.print()
-
 
 class SegmentList(ComponentCollection, collections.abc.Sequence):
     """A sequence of JBP segments"""
@@ -2320,9 +2336,9 @@ def __init__(self, name: str, data_size: int = 1):
         self._append(ImageSubheader("subheader"))
         self._append(BinaryPlaceholder("Data", data_size))
 
-    def print(self) -> None:
-        print(f"# ImageSegment {self.name}")
-        super().print()
+    def print(self, *, file=None) -> None:
+        print(f"# ImageSegment {self.name}", file=file)
+        super().print(file=file)
 
 
 class GraphicSubheader(Group):
@@ -2528,9 +2544,9 @@ def __init__(self, name: str, data_size: int = 1):
         self._append(GraphicSubheader("subheader"))
         self._append(BinaryPlaceholder("Data", data_size))
 
-    def print(self) -> None:
-        print(f"# GraphicSegment {self.name}")
-        super().print()
+    def print(self, *, file=None) -> None:
+        print(f"# GraphicSegment {self.name}", file=file)
+        super().print(file=file)
 
 
 class TextSubheader(Group):
@@ -2673,9 +2689,9 @@ def __init__(self, name: str, data_size: int = 1):
         self._append(TextSubheader("subheader"))
         self._append(BinaryPlaceholder("Data", data_size))
 
-    def print(self) -> None:
-        print(f"# TextSegment {self.name}")
-        super().print()
+    def print(self, *, file=None) -> None:
+        print(f"# TextSegment {self.name}", file=file)
+        super().print(file=file)
 
 
 class ReservedExtensionSegment(Group):
@@ -2692,9 +2708,9 @@ def __init__(self, name: str, subheader_size: int = LRESH_MIN, data_size: int =
         )
         self._append(BinaryPlaceholder("RESDATA", data_size))
 
-    def print(self) -> None:
-        print(f"# ReservedExtensionSegment {self.name}")
-        super().print()
+    def print(self, *, file=None) -> None:
+        print(f"# ReservedExtensionSegment {self.name}", file=file)
+        super().print(file=file)
 
 
 class DataExtensionSubheader(Group):
@@ -2924,9 +2940,9 @@ def _load_impl(self, fd):
         fd.seek(self.get_offset())
         super()._load_impl(fd)
 
-    def print(self) -> None:
-        print(f"# DESegment {self.name}")
-        super().print()
+    def print(self, *, file=None) -> None:
+        print(f"# DESegment {self.name}", file=file)
+        super().print(file=file)
 
 
 def _update_tre_lengths(header, hdl, ofl, hd):
@@ -3538,3 +3554,36 @@ def tre_factory(tretag: str) -> Tre:
         return tres[tretag]()
 
     return UnknownTre(tretag)
+
+
+class _JsonEncoder(json.JSONEncoder):
+    def __init__(self, *args, full_details=False, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.full_details = full_details
+
+    def default(self, obj):
+        if isinstance(obj, collections.abc.Mapping):
+            return dict(obj)
+        if isinstance(obj, bytes):
+            return list(obj)
+        if isinstance(obj, Field):
+            if self.full_details:
+                return {
+                    "size": obj.size,
+                    "offset": obj.get_offset(),
+                    "value": obj.value,
+                }
+            return obj.value
+        if isinstance(obj, BinaryPlaceholder):
+            if self.full_details:
+                return {
+                    "size": obj.size,
+                    "offset": obj.get_offset(),
+                    "value": "__binary__",
+                }
+            return f"__binary__ ({obj.get_size()} bytes)"
+        if isinstance(obj, SegmentList):
+            return list(obj)
+        if isinstance(obj, TreSequence):
+            return list(obj)
+        return super().default(obj)

test/test_core.py

@@ -1,6 +1,7 @@
 import datetime
 import filecmp
 import io
+import json
 import logging
 import os
 import pathlib
@@ -324,9 +325,20 @@ def test_fileheader(capsys):
     ntf.finalize()
     ntf.print()
     captured = capsys.readouterr()
-    assert "GraphicSegment" in captured.out
-    assert "TextSegment" in captured.out
-    assert "ReservedExtensionSegment" in captured.out
+    assert "GraphicSegment 1" in captured.out
+    assert "TextSegment 1" in captured.out
+    assert "ReservedExtensionSegment 1" in captured.out
+
+    buf = io.StringIO()
+    ntf.print(file=buf)
+    assert captured.out == buf.getvalue()
+
+    txt = ntf.as_text()
+    assert "GraphicSegment 1" in txt
+    assert "TextSegment 1" in txt
+    assert "ReservedExtensionSegment 1" in txt
+
+    assert "GraphicSegments" in json.loads(ntf.as_json())
 
 
 def test_imseg():

test/test_jbpy.py

@@ -1,4 +1,5 @@
 import io
+import json
 import os
 
 import pytest
@@ -17,6 +18,12 @@ def test_roundtrip_jitc_quicklook(filename, tmp_path):
     with filename.open("rb") as file:
         ntf.load(file)
 
+    txt = ntf.as_text()
+    assert "FHDR" in txt
+    assert "@" in txt
+
+    assert "FileHeader" in json.loads(ntf.as_json())
+
     copy_filename = tmp_path / "copy.nitf"
     with copy_filename.open("wb") as fd:
         ntf.dump(fd)