1#! /usr/bin/env python3
2
3# pdeps
4#
5# Find dependencies between a bunch of Python modules.
6#
7# Usage:
8#       pdeps file1.py file2.py ...
9#
10# Output:
11# Four tables separated by lines like '--- Closure ---':
12# 1) Direct dependencies, listing which module imports which other modules
13# 2) The inverse of (1)
14# 3) Indirect dependencies, or the closure of the above
15# 4) The inverse of (3)
16#
17# To do:
18# - command line options to select output type
19# - option to automatically scan the Python library for referenced modules
20# - option to limit output to particular modules
21
22
23import sys
24import re
25import os
26
27
28# Main program
29#
30def main():
31    args = sys.argv[1:]
32    if not args:
33        print('usage: pdeps file.py file.py ...')
34        return 2
35    #
36    table = {}
37    for arg in args:
38        process(arg, table)
39    #
40    print('--- Uses ---')
41    printresults(table)
42    #
43    print('--- Used By ---')
44    inv = inverse(table)
45    printresults(inv)
46    #
47    print('--- Closure of Uses ---')
48    reach = closure(table)
49    printresults(reach)
50    #
51    print('--- Closure of Used By ---')
52    invreach = inverse(reach)
53    printresults(invreach)
54    #
55    return 0
56
57
58# Compiled regular expressions to search for import statements
59#
60m_import = re.compile('^[ \t]*from[ \t]+([^ \t]+)[ \t]+')
61m_from = re.compile('^[ \t]*import[ \t]+([^#]+)')
62
63
64# Collect data from one file
65#
66def process(filename, table):
67    fp = open(filename, 'r')
68    mod = os.path.basename(filename)
69    if mod[-3:] == '.py':
70        mod = mod[:-3]
71    table[mod] = list = []
72    while 1:
73        line = fp.readline()
74        if not line: break
75        while line[-1:] == '\\':
76            nextline = fp.readline()
77            if not nextline: break
78            line = line[:-1] + nextline
79        m_found = m_import.match(line) or m_from.match(line)
80        if m_found:
81            (a, b), (a1, b1) = m_found.regs[:2]
82        else: continue
83        words = line[a1:b1].split(',')
84        # print '#', line, words
85        for word in words:
86            word = word.strip()
87            if word not in list:
88                list.append(word)
89    fp.close()
90
91
92# Compute closure (this is in fact totally general)
93#
94def closure(table):
95    modules = list(table.keys())
96    #
97    # Initialize reach with a copy of table
98    #
99    reach = {}
100    for mod in modules:
101        reach[mod] = table[mod][:]
102    #
103    # Iterate until no more change
104    #
105    change = 1
106    while change:
107        change = 0
108        for mod in modules:
109            for mo in reach[mod]:
110                if mo in modules:
111                    for m in reach[mo]:
112                        if m not in reach[mod]:
113                            reach[mod].append(m)
114                            change = 1
115    #
116    return reach
117
118
119# Invert a table (this is again totally general).
120# All keys of the original table are made keys of the inverse,
121# so there may be empty lists in the inverse.
122#
123def inverse(table):
124    inv = {}
125    for key in table.keys():
126        if key not in inv:
127            inv[key] = []
128        for item in table[key]:
129            store(inv, item, key)
130    return inv
131
132
133# Store "item" in "dict" under "key".
134# The dictionary maps keys to lists of items.
135# If there is no list for the key yet, it is created.
136#
137def store(dict, key, item):
138    if key in dict:
139        dict[key].append(item)
140    else:
141        dict[key] = [item]
142
143
144# Tabulate results neatly
145#
146def printresults(table):
147    modules = sorted(table.keys())
148    maxlen = 0
149    for mod in modules: maxlen = max(maxlen, len(mod))
150    for mod in modules:
151        list = sorted(table[mod])
152        print(mod.ljust(maxlen), ':', end=' ')
153        if mod in list:
154            print('(*)', end=' ')
155        for ref in list:
156            print(ref, end=' ')
157        print()
158
159
160# Call main and honor exit status
161if __name__ == '__main__':
162    try:
163        sys.exit(main())
164    except KeyboardInterrupt:
165        sys.exit(1)
166