的Python 3.6变量替换

Question

我有以下的dict对象：

AUTH_LDAP_USER_FLAGS_BY_GROUP = { 
    "is_active": "cn=active,ou=groups,dc=example,dc=com", 
    "is_staff": "cn=staff,ou=groups,dc=example,dc=com", 
    "is_superuser": "cn=superuser,ou=groups,dc=example,dc=com" 
} 

我想从变量定义的IT元素：

# Load environmental variables here 
hostname = os.environ['AUTH_LDAP_SERVER'] 
binduser = os.environ['AUTH_LDAP_BIND_USER'] 
bindgroup = os.environ['AUTH_LDAP_BIND_GROUP'] 
dc1 = os.environ['AUTH_LDAP_BIND_DC1'] 
dc2 = os.environ['AUTH_LDAP_BIND_DC2'] 
bindpassword = os.environ['AUTH_LDAP_PASSWORD'] 

AUTH_LDAP_USER_FLAGS_BY_GROUP = { 
    "is_active": "cn=active,{bindgroup},dc={dc1),dc={dc2}", 
    "is_staff": "cn=staff,{bindgroup},dc={dc1},dc={dc2}", 
    "is_superuser": "cn=administrators,{bindgroup},dc={dc1},dc={dc2}" 
} 

我怎样才能插入变量进入字典？

Answer 1

在python 3.6+中，您有f-strings。

AUTH_LDAP_USER_FLAGS_BY_GROUP = { 
    "is_active": f"cn=active,{bindgroup},dc={dc1},dc={dc2}", 
    "is_staff": f"cn=staff,{bindgroup},dc={dc1},dc={dc2}", 
    "is_superuser": f"cn=administrators,{bindgroup},dc={dc1},dc={dc2}" 
} 

如果你正在使用Python 3.5或以上，你可以使用format

AUTH_LDAP_USER_FLAGS_BY_GROUP = { 
    "is_active": "cn=active,{},dc={},dc={}".format(bindgroup, dc1, dc2), 
    "is_staff": "cn=staff,{},dc={},dc={}".format(bindgroup, dc1, dc2), 
    "is_superuser": "cn=administrators,{},dc={},dc={}".format(bindgroup, dc1, dc2) 
} 

Answer 2

您只需在要格式化的字符串前添加f即可。关于f-strings的文档。

AUTH_LDAP_USER_FLAGS_BY_GROUP = { 
    "is_active": f"cn=active,{bindgroup},dc={dc1},dc={dc2}", 
    "is_staff": f"cn=staff,{bindgroup},dc={dc1},dc={dc2}", 
    "is_superuser": f"cn=administrators,{bindgroup},dc={dc1},dc={dc2}" 
} 

而且，我会用os.getenv避免KeyError异常的。