Format Python scripts using yapf (#332)

diff --git a/cmake/scripts/gen_cov.sh b/cmake/scripts/gen_cov.sh
index a24b5aa..35fb3e8 100755
--- a/cmake/scripts/gen_cov.sh
+++ b/cmake/scripts/gen_cov.sh
@@ -6,7 +6,7 @@
 done
 
 LCOV=lcov
-LCOVOPT="--gcov-tool ${TEACLAVE_PROJECT_ROOT}/cmake/scripts/llvm-gcov"
+LCOVOPT="--gcov-tool ${TEACLAVE_PROJECT_ROOT}/cmake/scripts/llvm-gcov.sh"
 LCOV_REALPATH="${TEACLAVE_PROJECT_ROOT}/cmake/scripts/lcov_realpath.py"
 GENHTML=genhtml
 
diff --git a/cmake/scripts/gen_enclave_info_toml.py b/cmake/scripts/gen_enclave_info_toml.py
index 1bc30da..3eead05 100644
--- a/cmake/scripts/gen_enclave_info_toml.py
+++ b/cmake/scripts/gen_enclave_info_toml.py
@@ -1,10 +1,11 @@
+#!/usr/bin/env python3
 import sys
 
 
 def find_hex_value(content, section):
     index = content.index(section)
     # assume each element in content is ending with '\n'
-    hex_bytes = ''.join(content[index+1:index+3]).split()
+    hex_bytes = ''.join(content[index + 1:index + 3]).split()
     return ''.join(['%02x' % int(x, 16) for x in hex_bytes])
 
 
diff --git a/cmake/scripts/lcov_realpath.py b/cmake/scripts/lcov_realpath.py
index 45a0786..bf81277 100644
--- a/cmake/scripts/lcov_realpath.py
+++ b/cmake/scripts/lcov_realpath.py
@@ -1,3 +1,4 @@
+#!/usr/bin/env python3
 import os
 import sys
 
@@ -5,6 +6,6 @@
     for l in f:
         if l.startswith("SF:"):
             realpath = os.path.realpath(l[3:])
-            print "SF:" + realpath,
+            print("SF:" + realpath, end='')
         else:
-            print l,
+            print(l, end='')
diff --git a/cmake/scripts/llvm-gcov b/cmake/scripts/llvm-gcov.sh
similarity index 100%
rename from cmake/scripts/llvm-gcov
rename to cmake/scripts/llvm-gcov.sh
diff --git a/cmake/scripts/parse_cargo_packages.py b/cmake/scripts/parse_cargo_packages.py
index 372b122..46399a5 100644
--- a/cmake/scripts/parse_cargo_packages.py
+++ b/cmake/scripts/parse_cargo_packages.py
@@ -1,3 +1,4 @@
+#!/usr/bin/env python3
 '''
 [usage] python parse_cargo_package.py <cargo_toml_path> <teaclave_root>
 This script parses Cargo.toml to print three lists for CMake
@@ -67,17 +68,18 @@
     elif pkg_path == 'dcap':
         return 'dcap'
     else:
-        sys.stderr.write('[Error]: Unknown category for package_path {}\n'.format(pkg_path))
+        sys.stderr.write(
+            '[Error]: Unknown category for package_path {}\n'.format(pkg_path))
         sys.exit(-1)
 
 
 DEFAULT_EDL_LIB = "Enclave_common_t"
 PKG_NAME_TO_EDL_LIB = {
-        "teaclave_unit_tests_enclave" : "Enclave_fa_t",
-        "teaclave_execution_service_enclave" : "Enclave_fa_t",
-    }
+    "teaclave_unit_tests_enclave": "Enclave_fa_t",
+    "teaclave_execution_service_enclave": "Enclave_fa_t",
+}
 
-    
+
 def pkg_name_2_edl_lib_name(pkg_name):
     """
     Take pkg_name and return its configured edl libary name, default is DEFAULT_EDL_LIB.
@@ -110,8 +112,10 @@
         pkg_categories.append(pkg_path_2_category(pkg_path))
         edl_lib_names.append(pkg_name_2_edl_lib_name(pkg_name))
 
-    out = [":".join(pkg_names), ":".join(pkg_paths),
-           ":".join(pkg_categories), ":".join(edl_lib_names)]
+    out = [
+        ":".join(pkg_names), ":".join(pkg_paths), ":".join(pkg_categories),
+        ":".join(edl_lib_names)
+    ]
     sys.stdout.write("\n".join(out))
 
 
diff --git a/cmake/scripts/prep.sh b/cmake/scripts/prep.sh
index 3d08a2d..a7fca71 100755
--- a/cmake/scripts/prep.sh
+++ b/cmake/scripts/prep.sh
@@ -14,7 +14,7 @@
     [ -z "${!var}" ] && echo "Please set ${var}" && exit -1
 done
 
-${MT_SCRIPT_DIR}/setup_cmake_tomls ${CMAKE_SOURCE_DIR} ${CMAKE_BINARY_DIR}
+${MT_SCRIPT_DIR}/setup_cmake_tomls.py ${CMAKE_SOURCE_DIR} ${CMAKE_BINARY_DIR}
 mkdir -p ${TEACLAVE_OUT_DIR} ${TEACLAVE_TARGET_DIR} ${TEACLAVE_SERVICE_INSTALL_DIR} \
       ${TEACLAVE_EXAMPLE_INSTALL_DIR} ${TEACLAVE_CLI_INSTALL_DIR} \
       ${TEACLAVE_BIN_INSTALL_DIR} ${TEACLAVE_LIB_INSTALL_DIR} \
diff --git a/cmake/scripts/setup_cmake_tomls b/cmake/scripts/setup_cmake_tomls.py
similarity index 73%
rename from cmake/scripts/setup_cmake_tomls
rename to cmake/scripts/setup_cmake_tomls.py
index 19c6513..516f46d 100755
--- a/cmake/scripts/setup_cmake_tomls
+++ b/cmake/scripts/setup_cmake_tomls.py
@@ -1,6 +1,6 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 '''
-[usage] setup_cmake_tomls [project_root_dir] [project_build_dir]
+[usage] setup_cmake_tomls.py [project_root_dir] [project_build_dir]
 Create cmake_tomls under build_dir
 Create separate folders for unix_app|sgx_trusted|sgx_untrusted under build_dir/cmake_tomls
 Create symlinks for Cargo.*.toml and folders so cargo build can run in separate folders
@@ -11,13 +11,7 @@
 import sys
 
 # symlinks won't be created for the following directories
-SYM_FOLDER_BLACKLIST = [
-    'docs',
-    'cmake',
-    'out',
-    'bin',
-    'build'
-]
+SYM_FOLDER_BLACKLIST = ['docs', 'cmake', 'out', 'bin', 'build']
 
 CATEGORIES = ['sgx_trusted_lib', 'sgx_untrusted_app', 'unix_app']
 
@@ -31,7 +25,8 @@
 def filter_sym_dir(root_dir, name):
     """return true if name corresponds to a folder and is not in blacklist"""
     return not name.startswith(
-        '.') and not name in SYM_FOLDER_BLACKLIST and osp.isdir(osp.join(root_dir, name))
+        '.') and not name in SYM_FOLDER_BLACKLIST and osp.isdir(
+            osp.join(root_dir, name))
 
 
 def create_symlinks(root_dir, build_dir):
@@ -39,23 +34,24 @@
     exec_cmd('mkdir -p {build_dir}/cmake_tomls'.format(build_dir=build_dir))
 
     sym_folders = list(
-        filter(
-            lambda name: filter_sym_dir(
-                root_dir,
-                name),
-            os.listdir(root_dir)))
+        filter(lambda name: filter_sym_dir(root_dir, name),
+               os.listdir(root_dir)))
 
     for cate in CATEGORIES:
-        cate_dir = '{build_dir}/cmake_tomls/{cate}'.format(
-            build_dir=build_dir, cate=cate)
+        cate_dir = '{build_dir}/cmake_tomls/{cate}'.format(build_dir=build_dir,
+                                                           cate=cate)
         cmd = 'mkdir -p {cate_dir} && [ ! -f {cate_dir}/Cargo.toml ] && \
             ln -s {root_dir}/cmake/tomls/Cargo.{cate}.toml \
-            {cate_dir}/Cargo.toml'.format(root_dir=root_dir, cate=cate, cate_dir=cate_dir)
+            {cate_dir}/Cargo.toml'.format(root_dir=root_dir,
+                                          cate=cate,
+                                          cate_dir=cate_dir)
         exec_cmd(cmd)
 
         for folder in sym_folders:
             cmd = '[ ! -d {cate_dir}/{folder} ] && ln -sn {root_dir}/{folder} \
-                {cate_dir}/'.format(root_dir=root_dir, folder=folder, cate_dir=cate_dir)
+                {cate_dir}/'.format(root_dir=root_dir,
+                                    folder=folder,
+                                    cate_dir=cate_dir)
             exec_cmd(cmd)
 
 
@@ -80,14 +76,18 @@
         && cp -f {third_party_dir}/crates-io/config {build_dir}/cmake_tomls/{target}/.cargo/config \
         && sed -i 's/directory = "vendor"/directory = "third_party\/crates-io\/vendor"/' \
         {build_dir}/cmake_tomls/{target}/.cargo/config'''
-        cmd = cmd.format(build_dir=build_dir, third_party_dir=third_party_dir, target=target)
+        cmd = cmd.format(build_dir=build_dir,
+                         third_party_dir=third_party_dir,
+                         target=target)
         exec_cmd(cmd)
 
 
 def main():
     """setup tomls for cmake"""
     if len(sys.argv) != 3:
-        print('[usage] setup_cmake_tomls [project_root_dir] [project_build_dir]')
+        print(
+            '[usage] setup_cmake_tomls.py [project_root_dir] [project_build_dir]'
+        )
         sys.exit(-1)
     root_dir = sys.argv[1]
     build_dir = sys.argv[2]
diff --git a/examples/python/builtin_echo.py b/examples/python/builtin_echo.py
index fd980ce..d9569b2 100644
--- a/examples/python/builtin_echo.py
+++ b/examples/python/builtin_echo.py
@@ -2,20 +2,11 @@
 
 import sys
 
-from teaclave import (
-    AuthenticationService,
-    FrontendService,
-    AuthenticationClient,
-    FrontendClient
-)
-from utils import (
-    AUTHENTICATION_SERVICE_ADDRESS,
-    FRONTEND_SERVICE_ADDRESS,
-    AS_ROOT_CA_CERT_PATH,
-    ENCLAVE_INFO_PATH,
-    USER_ID,
-    USER_PASSWORD
-)
+from teaclave import (AuthenticationService, FrontendService,
+                      AuthenticationClient, FrontendClient)
+from utils import (AUTHENTICATION_SERVICE_ADDRESS, FRONTEND_SERVICE_ADDRESS,
+                   AS_ROOT_CA_CERT_PATH, ENCLAVE_INFO_PATH, USER_ID,
+                   USER_PASSWORD)
 
 
 class BuiltinEchoExample:
diff --git a/examples/python/builtin_gbdt_train.py b/examples/python/builtin_gbdt_train.py
index d2e03e3..7d72715 100644
--- a/examples/python/builtin_gbdt_train.py
+++ b/examples/python/builtin_gbdt_train.py
@@ -128,7 +128,7 @@
 
 def main():
     example = BuiltinGbdtExample(USER_ID, USER_PASSWORD)
-    rt = example.gbdt() 
+    rt = example.gbdt()
 
     print("[+] function return: ", rt)
 
diff --git a/examples/python/builtin_online_decrypt.py b/examples/python/builtin_online_decrypt.py
index 6bad1bf..d14cf7a 100644
--- a/examples/python/builtin_online_decrypt.py
+++ b/examples/python/builtin_online_decrypt.py
@@ -75,7 +75,7 @@
     ]
     nonce = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]
     encrypted_data = "CaZd8qSMMlBp8SjSXj2I4dQIuC9KkZ5DI/ATo1sWJw=="
-    algorithm = "aes256gcm" # Alogorithm can be "aes256gcm" or "aes128gcm"
+    algorithm = "aes256gcm"  # Alogorithm can be "aes256gcm" or "aes128gcm"
     rt = example.decrypt(key, nonce, encrypted_data, algorithm)
     print("[+] function return: ", rt)
 
diff --git a/examples/python/mesapy_echo.py b/examples/python/mesapy_echo.py
index 6536f94..570adc7 100644
--- a/examples/python/mesapy_echo.py
+++ b/examples/python/mesapy_echo.py
@@ -2,20 +2,11 @@
 
 import sys
 
-from teaclave import (
-    AuthenticationService,
-    FrontendService,
-    AuthenticationClient,
-    FrontendClient
-)
-from utils import (
-    AUTHENTICATION_SERVICE_ADDRESS,
-    FRONTEND_SERVICE_ADDRESS,
-    AS_ROOT_CA_CERT_PATH,
-    ENCLAVE_INFO_PATH,
-    USER_ID,
-    USER_PASSWORD
-)
+from teaclave import (AuthenticationService, FrontendService,
+                      AuthenticationClient, FrontendClient)
+from utils import (AUTHENTICATION_SERVICE_ADDRESS, FRONTEND_SERVICE_ADDRESS,
+                   AS_ROOT_CA_CERT_PATH, ENCLAVE_INFO_PATH, USER_ID,
+                   USER_PASSWORD)
 
 
 class MesaPyEchoExample:
@@ -23,7 +14,9 @@
         self.user_id = user_id
         self.user_password = user_password
 
-    def echo(self, payload_file="mesapy_echo_payload.py", message="Hello, Teaclave!"):
+    def echo(self,
+             payload_file="mesapy_echo_payload.py",
+             message="Hello, Teaclave!"):
         channel = AuthenticationService(AUTHENTICATION_SERVICE_ADDRESS,
                                         AS_ROOT_CA_CERT_PATH,
                                         ENCLAVE_INFO_PATH).connect()
diff --git a/examples/python/utils.py b/examples/python/utils.py
index 2bd4725..ee085de 100644
--- a/examples/python/utils.py
+++ b/examples/python/utils.py
@@ -20,4 +20,3 @@
 else:
     AS_ROOT_CA_CERT_PATH = "../../keys/" + AS_ROOT_CERT_FILENAME
     ENCLAVE_INFO_PATH = "../../release/tests/enclave_info.toml"
-
diff --git a/tests/scripts/functional_tests.py b/tests/scripts/functional_tests.py
index 1cf4e2b..0e6d0e6 100755
--- a/tests/scripts/functional_tests.py
+++ b/tests/scripts/functional_tests.py
@@ -78,8 +78,8 @@
     quote = base64.b64decode(quote)
 
     # get mr_enclave and mr_signer from the quote
-    mr_enclave = quote[112:112+32].hex()
-    mr_signer = quote[176:176+32].hex()
+    mr_enclave = quote[112:112 + 32].hex()
+    mr_signer = quote[176:176 + 32].hex()
 
     # get enclave_info
     enclave_info = toml.load(ENCLAVE_INFO_PATH)
@@ -94,7 +94,6 @@
 
 
 class TestAuthenticationService(unittest.TestCase):
-
     def setUp(self):
         sock = socket.create_connection(AUTHENTICATION_SERVICE_ADDRESS)
         self.socket = CONTEXT.wrap_socket(sock, server_hostname=HOSTNAME)
diff --git a/tests/scripts/simple_http_server.py b/tests/scripts/simple_http_server.py
index 3fe4aa4..5a0cd01 100644
--- a/tests/scripts/simple_http_server.py
+++ b/tests/scripts/simple_http_server.py
@@ -23,6 +23,7 @@
     else:
         port = 6789
     socketserver.TCPServer.allow_reuse_address = True
-    with socketserver.TCPServer(("localhost", port), HTTPRequestHandler) as httpd:
+    with socketserver.TCPServer(("localhost", port),
+                                HTTPRequestHandler) as httpd:
         print("serving at port", port)
         httpd.serve_forever()