Make configure script more lenient to the length of CUDA and cuDNN ve…

…rsions entered. (tensorflow#16853)

configure.py

@@ -827,6 +827,28 @@ def set_gcc_host_compiler_path(environ_cp):
   write_action_env_to_bazelrc('GCC_HOST_COMPILER_PATH', gcc_host_compiler_path)
 
 
+def reformat_version_sequence(version_str, sequence_count):
+  """Reformat the version string to have the given number of sequences.
+
+  For example:
+  Given (7, 2) -> 7.0
+        (7.0.1, 2) -> 7.0
+        (5, 1) -> 5
+        (5.0.3.2, 1) -> 5
+
+  Args:
+      version_str: String, the version string.
+      sequence_count: int, an integer.
+  Returns:
+      string, reformatted version string.
+  """
+  v = version_str.split('.')
+  if len(v) < sequence_count:
+    v = v + (['0'] * (sequence_count - len(v)))
+
+  return '.'.join(v[:sequence_count])
+
+
 def set_tf_cuda_version(environ_cp):
   """Set CUDA_TOOLKIT_PATH and TF_CUDA_VERSION."""
   ask_cuda_version = (
@@ -837,6 +859,7 @@ def set_tf_cuda_version(environ_cp):
     # Configure the Cuda SDK version to use.
     tf_cuda_version = get_from_env_or_user_or_default(
         environ_cp, 'TF_CUDA_VERSION', ask_cuda_version, _DEFAULT_CUDA_VERSION)
+    tf_cuda_version = reformat_version_sequence(str(tf_cuda_version), 2)
 
     # Find out where the CUDA toolkit is installed
     default_cuda_path = _DEFAULT_CUDA_PATH
@@ -893,6 +916,7 @@ def set_tf_cudnn_version(environ_cp):
     tf_cudnn_version = get_from_env_or_user_or_default(
         environ_cp, 'TF_CUDNN_VERSION', ask_cudnn_version,
         _DEFAULT_CUDNN_VERSION)
+    tf_cudnn_version = reformat_version_sequence(str(tf_cudnn_version) ,1)
 
     default_cudnn_path = environ_cp.get('CUDA_TOOLKIT_PATH')
     ask_cudnn_path = (r'Please specify the location where cuDNN %s library is '