File opened without the
with statement PTC-W0010
Anti-pattern
Critical
6 months ago
—
4 years old
Use the
with statement to open a file125
126 if dist == '':
127 if os.path.exists('/etc/system-release'):
128 release = open('/etc/system-release').read()129 if 'Amazon Linux AMI' in release:
130 dist = 'centos'
131Use the
with statement to open a file119
120 if dist == '':
121 if os.path.exists('/etc/os-release'):
122 release = open('/etc/os-release').read()123 if 'Arch Linux' in release:
124 dist = 'arch'
125Use the
with statement to open a file 80 for d in sorted(os.listdir(adapter_dir)):
81 props = {}
82 path = os.path.join(adapter_dir, d, 'state')
83 for l in open(path).read().splitlines(): 84 if ':' in l:
85 key, value = l.strip().split(':')
86 props[key] = value.strip()Use the
with statement to open a file 47 os.path.join(battery_dir, d, 'info'),
48 os.path.join(battery_dir, d, 'state'),
49 ]:
50 for l in open(path).read().splitlines(): 51 if ':' in l:
52 key, value = l.strip().split(':')
53 props[key] = value.strip()Use the
with statement to open a file193 target = os.path.join(path, name.replace('/', ''))
194 with open(target, 'wb') as f:
195 for i in range(len(os.listdir(chunk_dir))):
196 f.write(open(os.path.join(chunk_dir, str(i + 1)), 'rb').read())197
198 shutil.rmtree(chunk_dir)
199 targets.append(target)
Description
Opening a file using with statement is preferred as function open implements the context manager protocol that releases the resource when it is outside of the with block. Not doing so requires you to manually release the resource.
Bad practice
f = open('/tmp/.deepsource.toml', 'w')
f.write("config file.")
# No `f.close()` statement: file may remain unaccessible
Preferred:
with open('/tmp/.deepsource.toml', 'w') as f:
f.write("config file.")