Python determines a user's permissions on a file

In Python, we need to determine whether a file has read, write, and execute permissions for the current user. We can usually use the os.access function to achieve this, such as:

# 判断读权限
os.access(<my file>, os.R_OK)
# 判断写权限
os.access(<my file>, os.W_OK)
# 判断执行权限
os.access(<my file>, os.X_OK)

# 判断读、写、执行权限
os.access(<my file>, os.R_OK | os.W_OK | os.X_OK)

But if you want to determine whether any specified user has read, write, and execute permissions on a certain file, there is no default implementation in Python. At this time, we can judge through the following code snippet

import os
import pwd
import stat
 
def is_readable(cls, path, user):
  user_info = pwd.getpwnam(user)
  uid = user_info.pw_uid
  gid = user_info.pw_gid
  s = os.stat(path)
  mode = s[stat.ST_MODE]
  return (
    ((s[stat.ST_UID] == uid) and (mode & stat.S_IRUSR > 0)) or
    ((s[stat.ST_GID] == gid) and (mode & stat.S_IRGRP > 0)) or
    (mode & stat.S_IROTH > 0)

    )
def is_writable(cls, path, user):
  user_info = pwd.getpwnam(user)
  uid = user_info.pw_uid
  gid = user_info.pw_gid
  s = os.stat(path)
  mode = s[stat.ST_MODE]
  return (
    ((s[stat.ST_UID] == uid) and (mode & stat.S_IWUSR > 0)) or
    ((s[stat.ST_GID] == gid) and (mode & stat.S_IWGRP > 0)) or
    (mode & stat.S_IWOTH > 0)

    )


def is_executable(cls, path, user):
  user_info = pwd.getpwnam(user)
  uid = user_info.pw_uid
  gid = user_info.pw_gid
  s = os.stat(path)
  mode = s[stat.ST_MODE]
  return (
    ((s[stat.ST_UID] == uid) and (mode & stat.S_IXUSR > 0)) or
    ((s[stat.ST_GID] == gid) and (mode & stat.S_IXGRP > 0)) or
    (mode & stat.S_IXOTH > 0)

    )

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