test, contrib, refactor: use with when opening a file

contrib/devtools/copyright_header.py

@@ -320,15 +320,13 @@ def get_most_recent_git_change_year(filename):
 ################################################################################
 
 def read_file_lines(filename):
-    f = open(filename, 'r', encoding="utf8")
-    file_lines = f.readlines()
-    f.close()
+    with open(filename, 'r', encoding="utf8") as f:
+        file_lines = f.readlines()
     return file_lines
 
 def write_file_lines(filename, file_lines):
-    f = open(filename, 'w', encoding="utf8")
-    f.write(''.join(file_lines))
-    f.close()
+    with open(filename, 'w', encoding="utf8") as f:
+        f.write(''.join(file_lines))
 
 ################################################################################
 # update header years execution

contrib/linearize/linearize-data.py

@@ -34,12 +34,12 @@ def get_blk_dt(blk_hdr):
 # When getting the list of block hashes, undo any byte reversals.
 def get_block_hashes(settings):
     blkindex = []
-    f = open(settings['hashlist'], "r", encoding="utf8")
-    for line in f:
-        line = line.rstrip()
-        if settings['rev_hash_bytes'] == 'true':
-            line = bytes.fromhex(line)[::-1].hex()
-        blkindex.append(line)
+    with open(settings['hashlist'], "r", encoding="utf8") as f:
+        for line in f:
+            line = line.rstrip()
+            if settings['rev_hash_bytes'] == 'true':
+                line = bytes.fromhex(line)[::-1].hex()
+            blkindex.append(line)
 
     print("Read " + str(len(blkindex)) + " hashes")
 
@@ -249,19 +249,18 @@ if __name__ == '__main__':
         print("Usage: linearize-data.py CONFIG-FILE")
         sys.exit(1)
 
-    f = open(sys.argv[1], encoding="utf8")
-    for line in f:
-        # skip comment lines
-        m = re.search(r'^\s*#', line)
-        if m:
-            continue
+    with open(sys.argv[1], encoding="utf8") as f:
+        for line in f:
+            # skip comment lines
+            m = re.search(r'^\s*#', line)
+            if m:
+                continue
 
-        # parse key=value lines
-        m = re.search(r'^(\w+)\s*=\s*(\S.*)$', line)
-        if m is None:
-            continue
-        settings[m.group(1)] = m.group(2)
-    f.close()
+            # parse key=value lines
+            m = re.search(r'^(\w+)\s*=\s*(\S.*)$', line)
+            if m is None:
+                continue
+            settings[m.group(1)] = m.group(2)
 
     # Force hash byte format setting to be lowercase to make comparisons easier.
     # Also place upfront in case any settings need to know about it.

contrib/linearize/linearize-hashes.py

@@ -98,19 +98,18 @@ if __name__ == '__main__':
         print("Usage: linearize-hashes.py CONFIG-FILE")
         sys.exit(1)
 
-    f = open(sys.argv[1], encoding="utf8")
-    for line in f:
-        # skip comment lines
-        m = re.search(r'^\s*#', line)
-        if m:
-            continue
+    with open(sys.argv[1], encoding="utf8") as f:
+        for line in f:
+            # skip comment lines
+            m = re.search(r'^\s*#', line)
+            if m:
+                continue
 
-        # parse key=value lines
-        m = re.search(r'^(\w+)\s*=\s*(\S.*)$', line)
-        if m is None:
-            continue
-        settings[m.group(1)] = m.group(2)
-    f.close()
+            # parse key=value lines
+            m = re.search(r'^(\w+)\s*=\s*(\S.*)$', line)
+            if m is None:
+                continue
+            settings[m.group(1)] = m.group(2)
 
     if 'host' not in settings:
         settings['host'] = '127.0.0.1'

contrib/verify-commits/verify-commits.py

@@ -82,11 +82,16 @@ def main():
     # get directory of this program and read data files
     dirname = os.path.dirname(os.path.abspath(__file__))
     print("Using verify-commits data from " + dirname)
-    verified_root = open(dirname + "/trusted-git-root", "r", encoding="utf8").read().splitlines()[0]
-    verified_sha512_root = open(dirname + "/trusted-sha512-root-commit", "r", encoding="utf8").read().splitlines()[0]
-    revsig_allowed = open(dirname + "/allow-revsig-commits", "r", encoding="utf-8").read().splitlines()
-    unclean_merge_allowed = open(dirname + "/allow-unclean-merge-commits", "r", encoding="utf-8").read().splitlines()
-    incorrect_sha512_allowed = open(dirname + "/allow-incorrect-sha512-commits", "r", encoding="utf-8").read().splitlines()
+    with open(dirname + "/trusted-git-root", "r", encoding="utf8") as f:
+        verified_root = f.read().splitlines()[0]
+    with open(dirname + "/trusted-sha512-root-commit", "r", encoding="utf8") as f:
+        verified_sha512_root = f.read().splitlines()[0]
+    with open(dirname + "/allow-revsig-commits", "r", encoding="utf8") as f:
+        revsig_allowed = f.read().splitlines()
+    with open(dirname + "/allow-unclean-merge-commit", "r", encoding="utf8") as f:
+        unclean_merge_allowed = f.read().splitlines()
+    with open(dirname + "/allow-incorrect-sha512-commits", "r", encoding="utf8") as f:
+        incorrect_sha512_allowed = f.read().splitlines()
 
     # Set commit and branch and set variables
     current_commit = args.commit