Gymnast: It's not Acrobat

PDF parser written in Python 3 (backport to 2.7 in the works). This was designed to provide a Pythonic interface to access (and, eventually, write) Adobe PDF files. Some of attributes have non-Pythonic capitalization, but that is to match the underlying structure of the PDF document (doing otherwise would get very confusing).

##Usage (dev branch)

import requests
from gymnast import PdfDocument, PdfTextRenderer

url = 'http://www.census.gov/retail/mrts/www/data/pdf/ec_current.pdf'
r = requests.get(url)
pdf = PdfDocument(r.content).parse()
text = PdfTextRenderer(pdf.Pages[1], fixed_width=True).render()
print(text)

####Output:

     Table 1.   Estimated Quarterly U.S. Retail Sales: Total and E-commerce1 
      (Estimates are based on data from the Monthly Retail Trade Survey and administrative records.) 
                                    Retail Sales            E-commerce        Percent Change              Percent Change
                                (millions of dollars)      as a Percent       From Prior Quarter          From Same Quarter 
             Quarter                                            of                                            A Year Ago
                               Total      E-commerce       Total           Total      E-commerce         Total    E-commerce 
       Adjusted2
       3rd quarter 2015(p)   1,184,994       87,509         7.4           1.2            4.2           1.6          15.1
       2nd quarter 2015(r)   1,171,458       84,019         7.2           1.6            4.4           1.0          14.3
       1st quarter 2015      1,152,986       80,451         7.0           -1.4           3.7           1.8          14.8
       4th quarter 2014      1,169,143       77,558         6.6           0.3            2.0           3.8          14.0
       3rd quarter 2014(r)   1,165,943       76,041         6.5           0.5            3.5           4.0          15.4
       Not Adjusted
       3rd quarter 2015(p)   1,187,337       81,053         6.8           0.0            2.9           1.6          15.2
       2nd quarter 2015(r)   1,187,208       78,779         6.6           10.2           5.2           0.9          14.4
       1st quarter 2015      1,077,586       74,920         7.0          -12.1         -19.9           1.5          14.4
       4th quarter 2014      1,225,969       93,530         7.6           4.9           32.9           3.9          13.9
       3rd quarter 2014      1,168,187       70,351         6.0           -0.7           2.2           4.2          15.7
         (p) Preliminary estimate.    (r) Revised estimate.  
             1 E-commerce sales are sales of goods and services where  the buyer places an order, or the price and terms  of the sale  are negotiated over an Internet, mobile 
         device (M-commerce), extranet, Electronic Data Interchange (EDI) network, electronic mail, or other comparable online system. Payment may or may not be 
         made online. 
          2
          Estimates are adjusted for seasonal variation, but not for price changes.  Total sales estimates are also adjusted for trading-day differences and moving 
         holidays. 
...

##TODO (in no particular order)

• Features and functionality
  • Rewrite the parser and document class to lazy-load the document based on the xrefs table
  • Complete the base page renderer
  • Page Rendering
    • Getting the BaseRenderer class working
    • Implement a proof of concept extractor that just dumps strings
    • Get a bit fancier, assigning textblocks to lines and such
  • Handle page numbering more fully
    • Add a method to PdfDocument to get a page by number
    • Add propreties to PdfPage for the page number (both as an int and a formatted str according to PdfDocument.Root.PageLabels['Nums']) (first part done on dev branch)
  • Backport to Python 2.7 (about 80% done or so)
  • Font stuff
    • Carve the PdfFont class into an abstract PdfBaseFont and a PdfType1Font implementation
      • PdfFont.__new__ will pick the correct subclass based on the font's Subtype element
      • PdfBasefFont class will also have an abstract method for the glyph space to text space transformation
    • Add subcless for Type3 fonts
    • Add subcless for TrueType fonts
    • Add subcless for composite fonts
    • Add legacy support for the 14 standard fonts
    • Font-to-unicode CMAPs
  • Implement the remaining StreamFilters (will probably have the image ones return a PIL.Image)
    • RunLengthDecode
    • CCITTFaxDecode
    • JBIG2Decode
    • DCTDecode
    • JPXDecode
    • Crypt
  • Implement remaining object types
    • ObjStm (on dev branch)
    • XRef
    • Filespec
    • EmbeddedFile
    • CollectionItem / CollectionSubitem
    • XObject
  • Handle document encryption
  • Start on graphics stuff (maybe)
  • Interactive forms (AcroForms)
• Administrative
  • Write tests for existing code
  • Come up with a better name
  • Document everything much, much better internally
  • Package it up neatly and pypi it
  • Write some proper documentation