New subdivisioning of package, and added red warnings during testing

2026-08-09 11:40:16 +08:00 · 2015-08-04 16:46:47 +02:00
parent 085592de6a
commit 0ebf57e798
22 changed files with 65 additions and 95 deletions
@@ -0,0 +1,98 @@
+import urllib2
+import re
+
+def build_crs_table(savepath):
+    """
+    Build crs table of all equivalent format variations by scraping spatialreference.org.
+    Saves table as tab-delimited text file.
+    NOTE: Might take a while.
+
+    Arguments:
+    - *savepath*: The absolute or relative filepath to which to save the crs table, including the ".txt" extension. 
+    """
+    # create table
+    outfile = open(savepath, "wb")
+    
+    # create fields
+    fields = ["codetype", "code", "proj4", "ogcwkt", "esriwkt"]
+    outfile.write("\t".join(fields) + "\n")
+    
+    # make table from url requests
+    for codetype in ("epsg", "esri", "sr-org"):
+        print(codetype)
+        
+        # collect existing proj list
+        print("fetching list of available codes")
+        codelist = []
+        page = 1
+        while True:
+            try:
+                link = 'http://spatialreference.org/ref/%s/?page=%s' %(codetype,page)
+                html = urllib2.urlopen(link).read()
+                codes = [match.groups()[0] for match in re.finditer(r'/ref/'+codetype+'/(\d+)', html) ]
+                if not codes: break
+                print("page",page)
+                codelist.extend(codes)
+                page += 1
+            except:
+                break
+
+        print("fetching string formats for each projection")
+        for i,code in enumerate(codelist):
+            
+            # check if code exists
+            link = 'http://spatialreference.org/ref/%s/%s/' %(codetype,code)
+            urllib2.urlopen(link)
+            
+            # collect each projection format in a table row
+            row = [codetype, code]
+            for resulttype in ("proj4", "ogcwkt", "esriwkt"):
+                try:
+                    link = 'http://spatialreference.org/ref/%s/%s/%s/' %(codetype,code,resulttype)
+                    result = urllib2.urlopen(link).read()
+                    row.append(result)
+                except:
+                    pass
+
+            print("projection %i of %i added" %(i,len(codelist)) )
+            outfile.write("\t".join(row) + "\n")
+
+    # close the file
+    outfile.close()
+
+            
+def crscode_to_string(codetype, code, format):
+    """
+    Lookup crscode on spatialreference.org and return in specified format.
+
+    Arguments:
+    - *codetype*: "epsg", "esri", or "sr-org".
+    - *code*: The code.
+    - *format*: The crs format of the returned string. One of "ogcwkt", "esriwkt", or "proj4", but also several others...
+
+    Returns:
+    - Crs string in the specified format. 
+    """
+    link = 'http://spatialreference.org/ref/%s/%s/%s/' %(codetype,code,format)
+    result = urllib2.urlopen(link).read()
+    return result
+
+##def crsstring_to_string(string, newformat):
+##    """
+##    Search unknown crs string for a match on spatialreference.org.
+##    Not very reliable, the search engine does not properly lookup all text.
+##    If string is correct there should only be one correct match.
+##    Warning: Not finished yet.
+##    """
+##    link = 'http://spatialreference.org/ref/?search=%s' %string
+##    searchresults = urllib2.urlopen(link).read()
+##    # pick the first result
+##    # ...regex...
+##    # go to its url, with extension for the newformat
+##    link = 'http://spatialreference.org/ref/%s/%s/%s/' %(codetype,code,newformat)
+##    result = urllib2.urlopen(link).read()
+##    return result
+    
+
+
+