Allow files to be read from strings per #37

Adds a loads() method to the top level module which generates a GerberFile or ExcellonFile from a string

1 files changed, 39 insertions, 11 deletions

diff --git a/gerber/excellon.py b/gerber/excellon.py
index d89b349..ba8573d 100755
--- a/gerber/excellon.py
+++ b/gerber/excellon.py
@@ -25,6 +25,7 @@ This module provides Excellon file classes and parsing utilities
 

 import math

 import operator

+from cStringIO import StringIO

 

 from .excellon_statements import *

 from .cam import CamFile, FileSettings

@@ -46,9 +47,28 @@ def read(filename):
 

     """

     # File object should use settings from source file by default.

-    settings = FileSettings(**detect_excellon_format(filename))

+    with open(filename, 'r') as f:

+        data = f.read()

+    settings = FileSettings(**detect_excellon_format(data))

     return ExcellonParser(settings).parse(filename)

 

+def loads(data):

+    """ Read data from string and return an ExcellonFile

+    Parameters

+    ----------

+    data : string

+        string containing Excellon file contents

+

+    Returns

+    -------

+    file : :class:`gerber.excellon.ExcellonFile`

+        An ExcellonFile created from the specified file.

+

+    """

+    # File object should use settings from source file by default.

+    settings = FileSettings(**detect_excellon_format(data))

+    return ExcellonParser(settings).parse_raw(data)

+

 

 class DrillHit(object):

     def __init__(self, tool, position):

@@ -302,9 +322,12 @@ class ExcellonParser(object):
 

     def parse(self, filename):

         with open(filename, 'r') as f:

-            for line in f:

-                self._parse(line.strip())

-                

+            data = f.read()

+        return self.parse_raw(data, filename)

+

+    def parse_raw(self, data, filename=None):

+        for line in StringIO(data):

+            self._parse(line.strip())

         for stmt in self.statements:

             stmt.units = self.units

         return ExcellonFile(self.statements, self.tools, self.hits,

@@ -428,14 +451,13 @@ class ExcellonParser(object):
                             zeros=self.zeros, notation=self.notation)

 

 

-def detect_excellon_format(filename):

+def detect_excellon_format(data=None, filename=None):

     """ Detect excellon file decimal format and zero-suppression settings.

 

     Parameters

     ----------

-    filename : string

-        Name of the file to parse. This does not check if the file is actually

-        an Excellon file, so do that before calling this.

+    data : string

+        String containing contents of Excellon file.

 

     Returns

     -------

@@ -449,10 +471,16 @@ def detect_excellon_format(filename):
     detected_format = None

     zeros_options = ('leading', 'trailing', )

     format_options = ((2, 4), (2, 5), (3, 3),)

+    

+    if data is None and filename is None:

+        raise ValueError('Either data or filename arguments must be provided')

+    if data is None:

+        with open(filename, 'r') as f:

+            data = f.read()

 

     # Check for obvious clues:

     p = ExcellonParser()

-    p.parse(filename)

+    p.parse_raw(data)

 

     # Get zero_suppression from a unit statement

     zero_statements = [stmt.zeros for stmt in p.statements

@@ -485,8 +513,8 @@ def detect_excellon_format(filename):
             settings = FileSettings(zeros=zeros, format=fmt)

             try:

                 p = ExcellonParser(settings)

-                p.parse(filename)

-                size = tuple([t[1] - t[0] for t in p.bounds])

+                p.parse_raw(data)

+                size = tuple([t[0] - t[1] for t in p.bounds])

                 hole_area = 0.0

                 for hit in p.hits:

                     tool = hit.tool