MAINT: Use with statements for opening files in distutils

Not super important, but saves some lines. Only the low-hanging ones here.

Found while tracking down an unrelated ResourceWarning

5 files changed, 80 insertions, 101 deletions

diff --git a/numpy/distutils/command/build_src.py b/numpy/distutils/command/build_src.py
index 668bc23fe..6d5d305d2 100644
--- a/numpy/distutils/command/build_src.py
+++ b/numpy/distutils/command/build_src.py
@@ -28,20 +28,14 @@ def subst_vars(target, source, d):
     """Substitute any occurrence of @foo@ by d['foo'] from source file into
     target."""
     var = re.compile('@([a-zA-Z_]+)@')
-    fs = open(source, 'r')
-    try:
-        ft = open(target, 'w')
-        try:
+    with open(source, 'r') as fs:
+        with open(target, 'w') as ft:
             for l in fs:
                 m = var.search(l)
                 if m:
                     ft.write(l.replace('@%s@' % m.group(1), d[m.group(1)]))
                 else:
                     ft.write(l)
-        finally:
-            ft.close()
-    finally:
-        fs.close()
 
 class build_src(build_ext.build_ext):
 
@@ -425,9 +419,8 @@ class build_src(build_ext.build_ext):
                     else:
                         log.info("conv_template:> %s" % (target_file))
                         outstr = process_c_file(source)
-                    fid = open(target_file, 'w')
-                    fid.write(outstr)
-                    fid.close()
+                    with open(target_file, 'w') as fid:
+                        fid.write(outstr)
                 if _header_ext_match(target_file):
                     d = os.path.dirname(target_file)
                     if d not in include_dirs:
@@ -723,25 +716,23 @@ _has_c_header = re.compile(r'-[*]-\s*c\s*-[*]-', re.I).search
 _has_cpp_header = re.compile(r'-[*]-\s*c[+][+]\s*-[*]-', re.I).search
 
 def get_swig_target(source):
-    f = open(source, 'r')
-    result = None
-    line = f.readline()
-    if _has_cpp_header(line):
-        result = 'c++'
-    if _has_c_header(line):
-        result = 'c'
-    f.close()
+    with open(source, 'r') as f:
+        result = None
+        line = f.readline()
+        if _has_cpp_header(line):
+            result = 'c++'
+        if _has_c_header(line):
+            result = 'c'
     return result
 
 def get_swig_modulename(source):
-    f = open(source, 'r')
-    name = None
-    for line in f:
-        m = _swig_module_name_match(line)
-        if m:
-            name = m.group('name')
-            break
-    f.close()
+    with open(source, 'r') as f:
+        name = None
+        for line in f:
+            m = _swig_module_name_match(line)
+            if m:
+                name = m.group('name')
+                break
     return name
 
 def _find_swig_target(target_dir, name):
@@ -760,15 +751,14 @@ _f2py_user_module_name_match = re.compile(r'\s*python\s*module\s*(?P<name>[\w_]*
 
 def get_f2py_modulename(source):
     name = None
-    f = open(source)
-    for line in f:
-        m = _f2py_module_name_match(line)
-        if m:
-            if _f2py_user_module_name_match(line): # skip *__user__* names
-                continue
-            name = m.group('name')
-            break
-    f.close()
+    with open(source) as f:
+        for line in f:
+            m = _f2py_module_name_match(line)
+            if m:
+                if _f2py_user_module_name_match(line): # skip *__user__* names
+                    continue
+                name = m.group('name')
+                break
     return name
 
 ##########################################
diff --git a/numpy/distutils/command/install.py b/numpy/distutils/command/install.py
index a1dd47755..c74ae9446 100644
--- a/numpy/distutils/command/install.py
+++ b/numpy/distutils/command/install.py
@@ -64,16 +64,15 @@ class install(old_install):
             # bdist_rpm fails when INSTALLED_FILES contains
             # paths with spaces. Such paths must be enclosed
             # with double-quotes.
-            f = open(self.record, 'r')
-            lines = []
-            need_rewrite = False
-            for l in f:
-                l = l.rstrip()
-                if ' ' in l:
-                    need_rewrite = True
-                    l = '"%s"' % (l)
-                lines.append(l)
-            f.close()
+            with open(self.record, 'r') as f:
+                lines = []
+                need_rewrite = False
+                for l in f:
+                    l = l.rstrip()
+                    if ' ' in l:
+                        need_rewrite = True
+                        l = '"%s"' % (l)
+                    lines.append(l)
             if need_rewrite:
                 self.execute(write_file,
                              (self.record, lines),
diff --git a/numpy/distutils/fcompiler/ibm.py b/numpy/distutils/fcompiler/ibm.py
index c4cb2fca7..70d2132e1 100644
--- a/numpy/distutils/fcompiler/ibm.py
+++ b/numpy/distutils/fcompiler/ibm.py
@@ -78,15 +78,14 @@ class IBMFCompiler(FCompiler):
                 xlf_cfg = '/etc/opt/ibmcmp/xlf/%s/xlf.cfg' % version
             fo, new_cfg = make_temp_file(suffix='_xlf.cfg')
             log.info('Creating '+new_cfg)
-            fi = open(xlf_cfg, 'r')
-            crt1_match = re.compile(r'\s*crt\s*[=]\s*(?P<path>.*)/crt1.o').match
-            for line in fi:
-                m = crt1_match(line)
-                if m:
-                    fo.write('crt = %s/bundle1.o\n' % (m.group('path')))
-                else:
-                    fo.write(line)
-            fi.close()
+            with open(xlf_cfg, 'r') as fi:
+                crt1_match = re.compile(r'\s*crt\s*[=]\s*(?P<path>.*)/crt1.o').match
+                for line in fi:
+                    m = crt1_match(line)
+                    if m:
+                        fo.write('crt = %s/bundle1.o\n' % (m.group('path')))
+                    else:
+                        fo.write(line)
             fo.close()
             opt.append('-F'+new_cfg)
         return opt
diff --git a/numpy/distutils/line_endings.py b/numpy/distutils/line_endings.py
index 5ecb104ff..2420798ab 100644
--- a/numpy/distutils/line_endings.py
+++ b/numpy/distutils/line_endings.py
@@ -19,9 +19,8 @@ def dos2unix(file):
     newdata = re.sub("\r\n", "\n", data)
     if newdata != data:
         print('dos2unix:', file)
-        f = open(file, "wb")
-        f.write(newdata)
-        f.close()
+        with open(file, "wb") as f:
+            f.write(newdata)
         return file
     else:
         print(file, 'ok')
@@ -53,9 +52,8 @@ def unix2dos(file):
     newdata = re.sub("\n", "\r\n", newdata)
     if newdata != data:
         print('unix2dos:', file)
-        f = open(file, "wb")
-        f.write(newdata)
-        f.close()
+        with open(file, "wb") as f:
+            f.write(newdata)
         return file
     else:
         print(file, 'ok')
diff --git a/numpy/distutils/misc_util.py b/numpy/distutils/misc_util.py
index 5df4cced3..cba84bffa 100644
--- a/numpy/distutils/misc_util.py
+++ b/numpy/distutils/misc_util.py
@@ -218,15 +218,14 @@ def get_mathlibs(path=None):
             raise DistutilsError('_numpyconfig.h not found in numpy include '
                 'dirs %r' % (dirs,))
 
-    fid = open(config_file)
-    mathlibs = []
-    s = '#define MATHLIB'
-    for line in fid:
-        if line.startswith(s):
-            value = line[len(s):].strip()
-            if value:
-                mathlibs.extend(value.split(','))
-    fid.close()
+    with open(config_file) as fid:
+        mathlibs = []
+        s = '#define MATHLIB'
+        for line in fid:
+            if line.startswith(s):
+                value = line[len(s):].strip()
+                if value:
+                    mathlibs.extend(value.split(','))
     return mathlibs
 
 def minrelpath(path):
@@ -443,14 +442,13 @@ def _get_f90_modules(source):
     if not f90_ext_match(source):
         return []
     modules = []
-    f = open(source, 'r')
-    for line in f:
-        m = f90_module_name_match(line)
-        if m:
-            name = m.group('name')
-            modules.append(name)
-            # break  # XXX can we assume that there is one module per file?
-    f.close()
+    with open(source, 'r') as f:
+        for line in f:
+            m = f90_module_name_match(line)
+            if m:
+                name = m.group('name')
+                modules.append(name)
+                # break  # XXX can we assume that there is one module per file?
     return modules
 
 def is_string(s):
@@ -1848,9 +1846,8 @@ class Configuration(object):
         else:
             entries = njoin(path, '.svn', 'entries')
         if os.path.isfile(entries):
-            f = open(entries)
-            fstr = f.read()
-            f.close()
+            with open(entries) as f:
+                fstr = f.read()
             if fstr[:5] == '<?xml':  # pre 1.4
                 m = re.search(r'revision="(?P<revision>\d+)"', fstr)
                 if m:
@@ -1879,9 +1876,8 @@ class Configuration(object):
 
         if os.path.isfile(branch_fn):
             branch0 = None
-            f = open(branch_fn)
-            revision0 = f.read().strip()
-            f.close()
+            with open(branch_fn) as f:
+                revision0 = f.read().strip()
 
             branch_map = {}
             for line in file(branch_cache_fn, 'r'):
@@ -1994,9 +1990,8 @@ class Configuration(object):
                 if not os.path.isfile(target):
                     version = str(revision)
                     self.info('Creating %s (version=%r)' % (target, version))
-                    f = open(target, 'w')
-                    f.write('version = %r\n' % (version))
-                    f.close()
+                    with open(target, 'w') as f:
+                        f.write('version = %r\n' % (version))
 
                 def rm_file(f=target,p=self.info):
                     if delete:
@@ -2035,9 +2030,8 @@ class Configuration(object):
                 if not os.path.isfile(target):
                     version = str(revision)
                     self.info('Creating %s (version=%r)' % (target, version))
-                    f = open(target, 'w')
-                    f.write('version = %r\n' % (version))
-                    f.close()
+                    with open(target, 'w') as f:
+                        f.write('version = %r\n' % (version))
 
                 def rm_file(f=target,p=self.info):
                     if delete:
@@ -2273,13 +2267,13 @@ def generate_config_py(target):
     from numpy.distutils.system_info import system_info
     from distutils.dir_util import mkpath
     mkpath(os.path.dirname(target))
-    f = open(target, 'w')
-    f.write('# This file is generated by numpy\'s %s\n' % (os.path.basename(sys.argv[0])))
-    f.write('# It contains system_info results at the time of building this package.\n')
-    f.write('__all__ = ["get_info","show"]\n\n')
+    with open(target, 'w') as f:
+        f.write('# This file is generated by numpy\'s %s\n' % (os.path.basename(sys.argv[0])))
+        f.write('# It contains system_info results at the time of building this package.\n')
+        f.write('__all__ = ["get_info","show"]\n\n')
 
-    # For gfortran+msvc combination, extra shared libraries may exist
-    f.write("""
+        # For gfortran+msvc combination, extra shared libraries may exist
+        f.write("""
 
 import os
 import sys
@@ -2292,9 +2286,9 @@ if sys.platform == 'win32' and os.path.isdir(extra_dll_dir):
 
 """)
 
-    for k, i in system_info.saved_results.items():
-        f.write('%s=%r\n' % (k, i))
-    f.write(r'''
+        for k, i in system_info.saved_results.items():
+            f.write('%s=%r\n' % (k, i))
+        f.write(r'''
 def get_info(name):
     g = globals()
     return g.get(name, g.get(name + "_info", {}))
@@ -2310,9 +2304,8 @@ def show():
             if k == "sources" and len(v) > 200:
                 v = v[:60] + " ...\n... " + v[-60:]
             print("    %s = %s" % (k,v))
-    ''')
+        ''')
 
-    f.close()
     return target
 
 def msvc_version(compiler):