DOC: Add compression example (#792)

docs/index.rst

@@ -30,6 +30,7 @@ You can contribute to `PyPDF2 on Github <https://github.com/py-pdf/PyPDF2>`_.
    user/adding-pdf-annotations
    user/forms
    user/streaming-data
+   user/file-size
 
 
 .. toctree::

docs/user/comparisons.md

@@ -63,4 +63,9 @@ a large community behind it.
 And there are more:
 
 
-* [`pyfpdf`](https://github.com/reingart/pyfpdf)
+* [`pdfplumber`](https://pypi.org/project/pdfplumber/)
+
+## Document Generation
+
+There are (Python) [tools to generate PDF documents](https://github.com/py-pdf/awesome-pdf#generators).
+PyPDF2 is not one of them.

docs/user/file-size.md

@@ -0,0 +1,38 @@
+# Reduce PDF Size
+
+There are multiple ways to reduce the size of a given PDF file. The easiest
+one is to remove content (e.g. images) or pages. 
+
+## Remove images
+
+
+```python
+import PyPDF2
+
+reader = PyPDF2.PdfFileReader("example.pdf")
+writer = PyPDF2.PdfFileWriter()
+
+for page in reader.pages:
+    writer.addPage(page)
+
+writer.removeImages()
+
+with open("out.pdf", "wb") as f:
+    writer.write(f)
+```
+
+## Compression
+
+```python
+import PyPDF2
+
+reader = PyPDF2.PdfFileReader("example.pdf")
+writer = PyPDF2.PdfFileWriter()
+
+for page in reader.pages:
+    page.compressContentStreams()
+    writer.addPage(page)
+
+with open("out.pdf", "wb") as f:
+    writer.write(f)
+```

docs/user/robustness.md

@@ -37,4 +37,5 @@ Choosing `strict=True` means that PyPDF2 will raise an exception if a PDF does
 not follow the specification.
 
 Choosing `strict=False` means that PyPDF2 will try to be forgiving and do
-something reasonable, but it will log a warning message.
+something reasonable, but it will log a warning message. It is a best-effort
+approach.