Adjust Python code to follow PEP8

presentations/ICPC-Referat/Material/kosaraju.py

@@ -1,28 +1,29 @@
 #!/usr/bin/python
 # -*- coding: utf-8 -*-
 
-""" 
-    @source: http://codehiker.wordpress.com/2012/04/06/kosarajus-scc/
-    I made minor changs
+"""
+@source: http://codehiker.wordpress.com/2012/04/06/kosarajus-scc/
+I made minor changs
 """
 
 import sys
 sys.setrecursionlimit(300000)
 
-source  = 'SCC.txt'
-N       = 875714
+source = 'SCC.txt'
+N = 875714
 
-#globals
+# globals
 visited = {}
-finish  = {}
-leader  = {}
+finish = {}
+leader = {}
 
-def getG(source):
+
+def get_g(source):
     """ Read the Graph from a textfile """
-    G    = {}
+    G = {}
     Grev = {}
-    for i in range(1,N+1):
-        G[i]    = []
+    for i in range(1, N+1):
+        G[i] = []
         Grev[i] = []
     fin = open(source)
     for line in fin:
@@ -33,56 +34,61 @@ def getG(source):
     fin.close()
     return G, Grev
 
+
 def init():
-    for i in range(1,N+1):
-        visited[i]  = 0
-        finish[i]   = 0
-        leader[i]   = 0
+    for i in range(1, N+1):
+        visited[i] = 0
+        finish[i] = 0
+        leader[i] = 0
+
 
 def dfs(G, i):
     global t
-    visited[i]  = 1
-    leader[i]   = s
+    visited[i] = 1
+    leader[i] = s
     for j in G[i]:
-        if(visited[j]==0): dfs(G,j)
+        if(visited[j] == 0):
+            dfs(G, j)
     t = t + 1
     finish[i] = t
 
+
 def dfs_loop(G):
     global t
     global s
-    t = 0 #number of nodes processed so far
-    s = 0 #current source vertex
+    t = 0  # number of nodes processed so far
+    s = 0  # current source vertex
     i = N
-    while(i>0):
-        if(visited[i]==0):
-            s=i
-            dfs(G,i)
-        i=i-1
+    while(i > 0):
+        if(visited[i] == 0):
+            s = i
+            dfs(G, i)
+        i = i-1
 
 if __name__ == "__main__":
     init()
-    g, grev=getG()
-    dfs_loop(grev) #THE FIRST LOOP ON REVERSE GRAPH
+    g, grev = get_g()
+    dfs_loop(grev)  # THE FIRST LOOP ON REVERSE GRAPH
 
     # construct new graph
     newGraph = {}
     for i in range(1, N+1):
         temp = []
-        for x in g[i]: temp.append(finish[x])
+        for x in g[i]:
+            temp.append(finish[x])
         newGraph[finish[i]] = temp
 
     init()
-    dfs_loop(newGraph) #THE SECOND LOOP 
+    dfs_loop(newGraph)  # THE SECOND LOOP
 
     # statistics
-    lst  = sorted(leader.values())
+    lst = sorted(leader.values())
     stat = []
-    pre  = 0
-    for i in range(0,N-1):
+    pre = 0
+    for i in range(0, N-1):
         if lst[i] != lst[i+1]:
             stat.append(i + 1 - pre)
-            pre=i+1
+            pre = i+1
     stat.append(N-pre)
     L = sorted(stat)
     L.reverse()