test reading 1M ngrams.

common/io.py

@@ -1,3 +1,7 @@
+import os
+import datetime
+import zipfile
+
 
 def write_obj(file_name, obj):
     with open(file_name, 'w') as f:
@@ -9,31 +13,41 @@ def write_str(file_name, s):
         f.write(s)
 
 
-def write_line(f, s):
-    if isinstance(s, basestring):
-        f.write(s)
-    else:
-        f.write(str(s))
-    f.write('\n')
-
-
 def write_lines(file_name, lines):
     with open(file_name, 'w') as f:
         f.writelines(lines)
 
 
-def read_all(file_name):
-    with open(file_name) as f:
+def append_line(file_path, line):
+    with open(file_path, "a") as f:
+        f.write(line)
+        f.write('\n')
+
+
+def read_all(file_path):
+    with open(file_path) as f:
         return f.read()
 
 
-def read_lines(file_name):
-    with open(file_name) as f:
+def read_all_lines(file_path):
+    with open(file_path) as f:
         return f.readlines()
 
 
-import os
-import datetime
+def read_lines(file_path, n=10):
+    with open(file_path) as f:
+        i = 0
+        for line in f:
+            i += 1
+            if i <= n:
+                yield line
+            else:
+                break
+
+
+def zip_extract_all(zip_file, target_dir):
+    with zipfile.ZipFile(zip_file, 'r') as z:
+        z.extractall(target_dir)
 
 
 def modified_on(filename):
@@ -48,4 +62,5 @@ def accessed_on(filename):
 
 def created_on(filename):
     t = os.path.getctime(filename)
-    return datetime.datetime.fromtimestamp(t)
+    return datetime.datetime.fromtimestamp(t)
+