Don't require gzip or bz2 until the actual functionality is requested.

1 files changed, 7 insertions, 1 deletions

diff --git a/numpy/lib/io.py b/numpy/lib/io.py
index 6edf902e3..9e61ab2f8 100644
--- a/numpy/lib/io.py
+++ b/numpy/lib/io.py
@@ -8,7 +8,6 @@ __all__ = ['savetxt', 'loadtxt',
 
 import numpy as np
 import format
-import zipfile
 import cStringIO
 import tempfile
 import os
@@ -42,6 +41,9 @@ class NpzFile(object):
     with .files and the ZipFile object itself using .zip
     """
     def __init__(self, fid):
+        # Import is postponed to here since zipfile depends on gzip, an optional
+        # component of the so-called standard library.
+        import zipfile
         _zip = zipfile.ZipFile(fid)
         self._files = _zip.namelist()
         self.files = []
@@ -165,6 +167,10 @@ def savez(file, *args, **kwds):
     arr_0, arr_1, etc.
     """
 
+    # Import is postponed to here since zipfile depends on gzip, an optional
+    # component of the so-called standard library.
+    import zipfile
+
     if isinstance(file, str):
         if not file.endswith('.npz'):
             file = file + '.npz'