12 files changed, 67 insertions, 42 deletions
diff --git a/docs/examples/tutorial/external/atoi.py b/docs/examples/tutorial/external/atoi.py
new file mode 100644
index 000000000..250b26a5c
--- /dev/null
+++ b/docs/examples/tutorial/external/atoi.py
@@ -0,0 +1,6 @@
+from cython.cimports.libc.stdlib import atoi
+
+@cython.cfunc
+def parse_charptr_to_py_int(s: cython.p_char):
+    assert s is not cython.NULL, "byte string value is NULL"
+    return atoi(s)  # note: atoi() has no error detection!
diff --git a/docs/examples/tutorial/external/atoi.pyx b/docs/examples/tutorial/external/atoi.pyx
index 48643bbf2..ef1219854 100644
--- a/docs/examples/tutorial/external/atoi.pyx
+++ b/docs/examples/tutorial/external/atoi.pyx
@@ -1,5 +1,6 @@
-from libc.stdlib cimport atoi
-
-cdef parse_charptr_to_py_int(char* s):
-    assert s is not NULL, "byte string value is NULL"
-    return atoi(s)  # note: atoi() has no error detection!
+from libc.stdlib cimport atoi
+
+
+cdef parse_charptr_to_py_int(char* s):
+    assert s is not NULL, "byte string value is NULL"
+    return atoi(s)  # note: atoi() has no error detection!
diff --git a/docs/examples/tutorial/external/cpdef_sin.pyx b/docs/examples/tutorial/external/cpdef_sin.pyx
index 47e09f433..eee2326a4 100644
--- a/docs/examples/tutorial/external/cpdef_sin.pyx
+++ b/docs/examples/tutorial/external/cpdef_sin.pyx
@@ -1,7 +1,7 @@
-"""
->>> sin(0)
-0.0
-"""
-
-cdef extern from "math.h":
-    cpdef double sin(double x)
+"""
+>>> sin(0)
+0.0
+"""
+
+cdef extern from "math.h":
+    cpdef double sin(double x)
diff --git a/docs/examples/tutorial/external/keyword_args.pyx b/docs/examples/tutorial/external/keyword_args.pyx
index 327e4e08b..7c2a786cc 100644
--- a/docs/examples/tutorial/external/keyword_args.pyx
+++ b/docs/examples/tutorial/external/keyword_args.pyx
@@ -1,2 +1,2 @@
-cdef extern from "string.h":
-    char* strstr(const char *haystack, const char *needle)
+cdef extern from "string.h":
+    char* strstr(const char *haystack, const char *needle)
diff --git a/docs/examples/tutorial/external/keyword_args_call.py b/docs/examples/tutorial/external/keyword_args_call.py
new file mode 100644
index 000000000..b3b3f5049
--- /dev/null
+++ b/docs/examples/tutorial/external/keyword_args_call.py
@@ -0,0 +1,7 @@
+from cython.cimports.strstr import strstr
+
+def main():
+    data: cython.p_char = "hfvcakdfagbcffvschvxcdfgccbcfhvgcsnfxjh"
+
+    pos = strstr(needle='akd', haystack=data)
+    print(pos is not cython.NULL)
diff --git a/docs/examples/tutorial/external/keyword_args_call.pyx b/docs/examples/tutorial/external/keyword_args_call.pyx
index 4be5f755d..de2b6f2b2 100644
--- a/docs/examples/tutorial/external/keyword_args_call.pyx
+++ b/docs/examples/tutorial/external/keyword_args_call.pyx
@@ -1,7 +1,7 @@
-cdef extern from "string.h":
-    char* strstr(const char *haystack, const char *needle)
-
-cdef char* data = "hfvcakdfagbcffvschvxcdfgccbcfhvgcsnfxjh"
-
-cdef char* pos = strstr(needle='akd', haystack=data)
-print(pos is not NULL)
+cdef extern from "string.h":
+    char* strstr(const char *haystack, const char *needle)
+
+cdef char* data = "hfvcakdfagbcffvschvxcdfgccbcfhvgcsnfxjh"
+
+cdef char* pos = strstr(needle='akd', haystack=data)
+print(pos is not NULL)
diff --git a/docs/examples/tutorial/external/libc_sin.py b/docs/examples/tutorial/external/libc_sin.py
new file mode 100644
index 000000000..f4223253d
--- /dev/null
+++ b/docs/examples/tutorial/external/libc_sin.py
@@ -0,0 +1,5 @@
+from cython.cimports.libc.math import sin
+
+@cython.cfunc
+def f(x: cython.double) -> cython.double:
+    return sin(x * x)
diff --git a/docs/examples/tutorial/external/libc_sin.pyx b/docs/examples/tutorial/external/libc_sin.pyx
index 25a4430e3..2de8444d6 100644
--- a/docs/examples/tutorial/external/libc_sin.pyx
+++ b/docs/examples/tutorial/external/libc_sin.pyx
@@ -1,4 +1,5 @@
-from libc.math cimport sin
-
-cdef double f(double x):
-    return sin(x * x)
+from libc.math cimport sin
+
+
+cdef double f(double x):
+    return sin(x * x)
diff --git a/docs/examples/tutorial/external/py_version_hex.py b/docs/examples/tutorial/external/py_version_hex.py
new file mode 100644
index 000000000..3b19d0d02
--- /dev/null
+++ b/docs/examples/tutorial/external/py_version_hex.py
@@ -0,0 +1,4 @@
+from cython.cimports.cpython.version import PY_VERSION_HEX
+
+# Python version >= 3.2 final ?
+print(PY_VERSION_HEX >= 0x030200F0)
diff --git a/docs/examples/tutorial/external/py_version_hex.pyx b/docs/examples/tutorial/external/py_version_hex.pyx
index d732b00e7..e33f207c1 100644
--- a/docs/examples/tutorial/external/py_version_hex.pyx
+++ b/docs/examples/tutorial/external/py_version_hex.pyx
@@ -1,4 +1,4 @@
-from cpython.version cimport PY_VERSION_HEX
-
-# Python version >= 3.2 final ?
-print(PY_VERSION_HEX >= 0x030200F0)
+from cpython.version cimport PY_VERSION_HEX
+
+# Python version >= 3.2 final ?
+print(PY_VERSION_HEX >= 0x030200F0)
diff --git a/docs/examples/tutorial/external/setup.py b/docs/examples/tutorial/external/setup.py
index 653214c84..289bc9534 100644
--- a/docs/examples/tutorial/external/setup.py
+++ b/docs/examples/tutorial/external/setup.py
@@ -1,13 +1,12 @@
-from distutils.core import setup
-from distutils.extension import Extension
-from Cython.Build import cythonize
-
-ext_modules = [
-    Extension("demo",
-              sources=["demo.pyx"],
-              libraries=["m"]  # Unix-like specific
-              )
-]
-
-setup(name="Demos",
-      ext_modules=cythonize(ext_modules))
+from setuptools import Extension, setup
+from Cython.Build import cythonize
+
+ext_modules = [
+    Extension("demo",
+              sources=["demo.pyx"],
+              libraries=["m"]  # Unix-like specific
+              )
+]
+
+setup(name="Demos",
+      ext_modules=cythonize(ext_modules))
diff --git a/docs/examples/tutorial/external/strstr.pxd b/docs/examples/tutorial/external/strstr.pxd
new file mode 100644
index 000000000..7c2a786cc
--- /dev/null
+++ b/docs/examples/tutorial/external/strstr.pxd
@@ -0,0 +1,2 @@
+cdef extern from "string.h":
+    char* strstr(const char *haystack, const char *needle)