Merge pull request #13720 from eric-wieser/more-with-statements

MAINT/BUG: Manage more files with with statements

6 files changed, 63 insertions, 86 deletions

diff --git a/numpy/core/code_generators/genapi.py b/numpy/core/code_generators/genapi.py
index 4aca2373c..923c34425 100644
--- a/numpy/core/code_generators/genapi.py
+++ b/numpy/core/code_generators/genapi.py
@@ -483,14 +483,11 @@ def get_versions_hash():
     d = []
 
     file = os.path.join(os.path.dirname(__file__), 'cversions.txt')
-    fid = open(file, 'r')
-    try:
+    with open(file, 'r') as fid:
         for line in fid:
             m = VERRE.match(line)
             if m:
                 d.append((int(m.group(1), 16), m.group(2)))
-    finally:
-        fid.close()
 
     return dict(d)
 
diff --git a/numpy/core/records.py b/numpy/core/records.py
index 2adcdae61..659ffa42b 100644
--- a/numpy/core/records.py
+++ b/numpy/core/records.py
@@ -42,7 +42,9 @@ from collections import Counter, OrderedDict
 
 from . import numeric as sb
 from . import numerictypes as nt
-from numpy.compat import isfileobj, bytes, long, unicode, os_fspath
+from numpy.compat import (
+    isfileobj, bytes, long, unicode, os_fspath, contextlib_nullcontext
+)
 from numpy.core.overrides import set_module
 from .arrayprint import get_printoptions
 
@@ -777,44 +779,42 @@ def fromfile(fd, dtype=None, shape=None, offset=0, formats=None,
 
     if isfileobj(fd):
         # file already opened
-        name = 0
+        ctx = contextlib_nullcontext(fd)
     else:
         # open file
-        fd = open(os_fspath(fd), 'rb')
-        name = 1
+        ctx = open(os_fspath(fd), 'rb')
 
-    if (offset > 0):
-        fd.seek(offset, 1)
-    size = get_remaining_size(fd)
+    with ctx as fd:
+        if (offset > 0):
+            fd.seek(offset, 1)
+        size = get_remaining_size(fd)
 
-    if dtype is not None:
-        descr = sb.dtype(dtype)
-    else:
-        descr = format_parser(formats, names, titles, aligned, byteorder)._descr
+        if dtype is not None:
+            descr = sb.dtype(dtype)
+        else:
+            descr = format_parser(formats, names, titles, aligned, byteorder)._descr
 
-    itemsize = descr.itemsize
+        itemsize = descr.itemsize
 
-    shapeprod = sb.array(shape).prod(dtype=nt.intp)
-    shapesize = shapeprod * itemsize
-    if shapesize < 0:
-        shape = list(shape)
-        shape[shape.index(-1)] = size // -shapesize
-        shape = tuple(shape)
         shapeprod = sb.array(shape).prod(dtype=nt.intp)
+        shapesize = shapeprod * itemsize
+        if shapesize < 0:
+            shape = list(shape)
+            shape[shape.index(-1)] = size // -shapesize
+            shape = tuple(shape)
+            shapeprod = sb.array(shape).prod(dtype=nt.intp)
 
-    nbytes = shapeprod * itemsize
+        nbytes = shapeprod * itemsize
 
-    if nbytes > size:
-        raise ValueError(
-                "Not enough bytes left in file for specified shape and type")
+        if nbytes > size:
+            raise ValueError(
+                    "Not enough bytes left in file for specified shape and type")
 
-    # create the array
-    _array = recarray(shape, descr)
-    nbytesread = fd.readinto(_array.data)
-    if nbytesread != nbytes:
-        raise IOError("Didn't read as many bytes as expected")
-    if name:
-        fd.close()
+        # create the array
+        _array = recarray(shape, descr)
+        nbytesread = fd.readinto(_array.data)
+        if nbytesread != nbytes:
+            raise IOError("Didn't read as many bytes as expected")
 
     return _array
 
diff --git a/numpy/core/setup_common.py b/numpy/core/setup_common.py
index 32d52d93e..bf6abcf02 100644
--- a/numpy/core/setup_common.py
+++ b/numpy/core/setup_common.py
@@ -312,30 +312,24 @@ def pyod(filename):
     def _pyod2():
         out = []
 
-        fid = open(filename, 'rb')
-        try:
+        with open(filename, 'rb') as fid:
             yo = [int(oct(int(binascii.b2a_hex(o), 16))) for o in fid.read()]
-            for i in range(0, len(yo), 16):
-                line = ['%07d' % int(oct(i))]
-                line.extend(['%03d' % c for c in yo[i:i+16]])
-                out.append(" ".join(line))
-            return out
-        finally:
-            fid.close()
+        for i in range(0, len(yo), 16):
+            line = ['%07d' % int(oct(i))]
+            line.extend(['%03d' % c for c in yo[i:i+16]])
+            out.append(" ".join(line))
+        return out
 
     def _pyod3():
         out = []
 
-        fid = open(filename, 'rb')
-        try:
+        with open(filename, 'rb') as fid:
             yo2 = [oct(o)[2:] for o in fid.read()]
-            for i in range(0, len(yo2), 16):
-                line = ['%07d' % int(oct(i)[2:])]
-                line.extend(['%03d' % int(c) for c in yo2[i:i+16]])
-                out.append(" ".join(line))
-            return out
-        finally:
-            fid.close()
+        for i in range(0, len(yo2), 16):
+            line = ['%07d' % int(oct(i)[2:])]
+            line.extend(['%03d' % int(c) for c in yo2[i:i+16]])
+            out.append(" ".join(line))
+        return out
 
     if sys.version_info[0] < 3:
         return _pyod2()
diff --git a/numpy/distutils/system_info.py b/numpy/distutils/system_info.py
index ba4ad4643..f169dba59 100644
--- a/numpy/distutils/system_info.py
+++ b/numpy/distutils/system_info.py
@@ -301,26 +301,21 @@ else:
             default_x11_include_dirs.extend(['/usr/lib/X11/include',
                                              '/usr/include/X11'])
 
-    tmp = None
-    try:
-        # Explicitly open/close file to avoid ResourceWarning when
-        # tests are run in debug mode Python 3.
-        tmp = open(os.devnull, 'w')
-        p = subprocess.Popen(["gcc", "-print-multiarch"], stdout=subprocess.PIPE,
-                     stderr=tmp)
-    except (OSError, DistutilsError):
-        # OSError if gcc is not installed, or SandboxViolation (DistutilsError
-        # subclass) if an old setuptools bug is triggered (see gh-3160).
-        pass
-    else:
-        triplet = str(p.communicate()[0].decode().strip())
-        if p.returncode == 0:
-            # gcc supports the "-print-multiarch" option
-            default_x11_lib_dirs += [os.path.join("/usr/lib/", triplet)]
-            default_lib_dirs += [os.path.join("/usr/lib/", triplet)]
-    finally:
-        if tmp is not None:
-            tmp.close()
+    with open(os.devnull, 'w') as tmp:
+        try:
+            p = subprocess.Popen(["gcc", "-print-multiarch"], stdout=subprocess.PIPE,
+                         stderr=tmp)
+        except (OSError, DistutilsError):
+            # OSError if gcc is not installed, or SandboxViolation (DistutilsError
+            # subclass) if an old setuptools bug is triggered (see gh-3160).
+            pass
+        else:
+            triplet = str(p.communicate()[0].decode().strip())
+            if p.returncode == 0:
+                # gcc supports the "-print-multiarch" option
+                default_x11_lib_dirs += [os.path.join("/usr/lib/", triplet)]
+                default_lib_dirs += [os.path.join("/usr/lib/", triplet)]
+
 
 if os.path.join(sys.prefix, 'lib') not in default_lib_dirs:
     default_lib_dirs.insert(0, os.path.join(sys.prefix, 'lib'))
diff --git a/numpy/lib/_datasource.py b/numpy/lib/_datasource.py
index 816f7624e..0d71375c2 100644
--- a/numpy/lib/_datasource.py
+++ b/numpy/lib/_datasource.py
@@ -41,6 +41,7 @@ import sys
 import warnings
 import shutil
 import io
+from contextlib import closing
 
 from numpy.core.overrides import set_module
 
@@ -414,13 +415,9 @@ class DataSource(object):
         # TODO: Doesn't handle compressed files!
         if self._isurl(path):
             try:
-                openedurl = urlopen(path)
-                f = _open(upath, 'wb')
-                try:
-                    shutil.copyfileobj(openedurl, f)
-                finally:
-                    f.close()
-                    openedurl.close()
+                with closing(urlopen(path)) as openedurl:
+                    with _open(upath, 'wb') as f:
+                        shutil.copyfileobj(openedurl, f)
             except URLError:
                 raise URLError("URL not found: %s" % path)
         else:
diff --git a/numpy/lib/format.py b/numpy/lib/format.py
index cd8700051..f5f3b28d3 100644
--- a/numpy/lib/format.py
+++ b/numpy/lib/format.py
@@ -841,16 +841,12 @@ def open_memmap(filename, mode='r+', dtype=None, shape=None,
             shape=shape,
         )
         # If we got here, then it should be safe to create the file.
-        fp = open(os_fspath(filename), mode+'b')
-        try:
+        with open(os_fspath(filename), mode+'b') as fp:
             _write_array_header(fp, d, version)
             offset = fp.tell()
-        finally:
-            fp.close()
     else:
         # Read the header of the file first.
-        fp = open(os_fspath(filename), 'rb')
-        try:
+        with open(os_fspath(filename), 'rb') as fp:
             version = read_magic(fp)
             _check_version(version)
 
@@ -859,8 +855,6 @@ def open_memmap(filename, mode='r+', dtype=None, shape=None,
                 msg = "Array can't be memory-mapped: Python objects in dtype."
                 raise ValueError(msg)
             offset = fp.tell()
-        finally:
-            fp.close()
 
     if fortran_order:
         order = 'F'