Best print and compare buffers.

.gitignore

@@ -87,3 +87,5 @@ ENV/
 
 # Rope project settings
 .ropeproject
+
+.directory

cmpreqs/compare_requirements.py

@@ -1,5 +1,6 @@
 #!/usr/bin/env python
-
+import subprocess
+from io import StringIO
 
 def get_version(line):
     if 'git+' in line or 'hg+' in line:
@@ -19,9 +20,9 @@ def get_package_name(line):
         return line.split('==')[0]
 
 
-def get_requirements(file):
+def get_requirements(indata):
     requirements = {}
-    lines = open(file).readlines()
+    lines = indata.readlines()
     for line in lines:
         if line.startswith('#'):
             continue
@@ -32,25 +33,56 @@ def get_requirements(file):
 
 
 def req_not_in(requirements1, requirements2):
-    return set(requirements1) - set(requirements2)
+    return {key: requirements1[key] for key in list(set(requirements1) - set(requirements2))}
+
+
+def print_columns(rows, titles=False):
+    rows = [titles] + rows if titles else rows
+    widths = [max(map(len, map(str, col))) for col in zip(*rows)]
+    if titles:
+        rows = [rows[0]] + [['-' * width for width in widths]] + rows[1:]
+    for row in rows:
+        print("  ".join((str(val).ljust(width) for val, width in zip(row, widths))))
 
 
-def compare(file1, file2):
-    requirements1 = get_requirements(file1)
-    requirements2 = get_requirements(file2)
-    print('{} <> {}'.format(file1, file2))
-    for name, version in requirements1.items():
-        if not name in requirements2:
-            continue
-        version2 = requirements2[name]
-        print('{}: {} {} {}'.format(name, version,'==' if version == version2 else '!=', version2))
-    not_in = {file1: [requirements2, requirements1], file2: [requirements1, requirements2]}
+def get_input_title(indata, index=None):
+    return getattr(indata, 'name', 'Input {}'.format(index or '?'))
+
+
+def print_title(name):
+    print()
+    print(name)
+    print('=' * len(name))
+
+
+def compare(input1, input2):
+    requirements1 = get_requirements(input1)
+    requirements2 = get_requirements(input2)
+    title1, title2 = get_input_title(input1, 1), get_input_title(input2, 2)
+    reqs = {name: (version, requirements2[name]) for name, version
+            in requirements1.items() if name in requirements2}
+    print_title('Different dependencies')
+    print_columns([[name, ver[0], ver[1]] for name, ver in reqs.items()
+                   if ver[0] != ver[1]], ['Name', title1, title2])
+    print_title('Equal dependencies')
+    print_columns([[name, ver[0]] for name, ver in reqs.items()
+                   if ver[0] == ver[1]], ['Name', 'Version'])
+    not_in = {title2: [requirements2, requirements1], title1: [requirements1, requirements2]}
     for file, reqs in not_in.items():
-        print('\n')
-        for req in req_not_in(*reqs):
-            print('{} not present in file {}'.format(req, file))
-
+        print_title('Only available on {}'.format(file))
+        print_columns([[name, ver] for name, ver in req_not_in(*reqs).items()], ['Name', 'Version'])
+
+
+def read_freeze():
+    return StringIO(subprocess.check_output(['pip', 'freeze']).decode('utf-8'))
 
+
+def read_pipdeptree():
+    data = subprocess.check_output(['pipdeptree']).decode('utf-8')
+    data = [x for x in data.split('\n') if x and not x[0] in ['-', ' ', '*']]
+    return StringIO('\n'.join(data))
+
+
 if __name__ == '__main__':
     import sys
-    compare(sys.argv[1], sys.argv[2])
+    compare(open(sys.argv[1]), open(sys.argv[2]))

scripts/cmpreqs

@@ -0,0 +1,23 @@
+#!/usr/bin/env python
+"""Compare requirements files created by Pip (Python)
+"""
+from cmpreqs.compare_requirements import compare, read_freeze, read_pipdeptree
+
+if __name__ == '__main__':
+    import sys
+    import argparse
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument('req1', nargs='?', help='First requirement file',
+                        default='requirements.txt')
+    parser.add_argument('req2', nargs='?',
+                        help='Second requirement file. By default, uses pip freeze.')
+    parser.add_argument('--pipdeptree', action='store_true')
+    args = parser.parse_args()
+    if args.req2:
+        req2 = open(args.req2)
+    elif args.pipdeptree:
+        req2 = read_pipdeptree()
+    else:
+        req2 = read_freeze()
+    compare(open(args.req1), req2)
+