# pip install jproperties\r\n<\/code><\/pre>\nHow to read a properties file in Python.<\/h2>\n
I have made a properties file specifically for our example, named app-config.properties.<\/p>\n
# Database<\/span> Credentials<\/span>\r\nDB_HOST<\/span>=<\/span>localhost\r\nDB_SCHEMA<\/span>=<\/span>Test<\/span>\r\nDB_User<\/span>=<\/span>root\r\nDB_PWD<\/span>=<\/span>root@neon<\/span>\r\n<\/code><\/pre>\nThe initial action is to bring the Properties object into our Python program and create an instance of it.<\/p>\n
from<\/span> jproperties import<\/span> Properties\r\n\r\nconfigs =<\/span> Properties(<\/span>)<\/span>\r\n<\/code><\/pre>\nOur next move involves loading the properties file into the Properties object.<\/p>\n
with<\/span> open<\/span>(<\/span>'app-config.properties'<\/span>,<\/span> 'rb'<\/span>)<\/span> as<\/span> config_file:<\/span>\r\n configs.<\/span>load(<\/span>config_file)<\/span>\r\n<\/code><\/pre>\nSuggested literature: Understanding the Python with Statement<\/p>\n
We have the option to retrieve a specific attribute by utilizing the get() function or by accessing it through the index. The Properties object closely resembles a Python Dictionary.<\/p>\n
The PropertyTuple object holds the value and consists of two named tuple values – data and meta. Although jproperties also support properties metadata, it is not relevant to us in this context.<\/p>\n
print<\/span>(<\/span>configs.<\/span>get(<\/span>\"DB_User\"<\/span>)<\/span>)<\/span> \r\n# PropertyTuple(data='root', meta={})<\/span>\r\n\r\nprint<\/span>(<\/span>f'Database User: <\/span>{<\/span>configs.<\/span>get(<\/span>\"DB_User\"<\/span>)<\/span>.<\/span>data}<\/span><\/span>'<\/span><\/span>)<\/span> \r\n# Database User: root<\/span>\r\n\r\nprint<\/span>(<\/span>f'Database Password: <\/span>{<\/span>configs[<\/span>\"DB_PWD\"<\/span>]<\/span>.<\/span>data}<\/span><\/span>'<\/span><\/span>)<\/span> \r\n# Database Password: root@neon<\/span>\r\n<\/code><\/pre>\nOne option for native paraphrasing could be:
\n“To obtain the number of properties, we can utilize the len() function.”<\/p>\n
print<\/span>(<\/span>f'Properties Count: <\/span>{<\/span>len<\/span>(<\/span>configs)<\/span>}<\/span><\/span>'<\/span><\/span>)<\/span> \r\n# Properties Count: 4<\/span>\r\n<\/code><\/pre>\nWhat happens if the key is not present?<\/h2>\n
If the key is not present, the get() function will provide None as the output.<\/p>\n
random_value =<\/span> configs.<\/span>get(<\/span>\"Random_Key\"<\/span>)<\/span>\r\nprint<\/span>(<\/span>random_value)<\/span> # None<\/span>\r\n<\/code><\/pre>\nHowever, if we employ the index, a KeyError will be raised. In such a scenario, it is more preferable to handle this exception using a try-except block.<\/p>\n
try<\/span>:<\/span>\r\n random_value =<\/span> configs[<\/span>\"Random_Key\"<\/span>]<\/span>\r\n print<\/span>(<\/span>random_value)<\/span>\r\nexcept<\/span> KeyError as<\/span> ke:<\/span>\r\n print<\/span>(<\/span>f'<\/span>{<\/span>ke}<\/span><\/span>, lookup key was \"Random_Key\"'<\/span><\/span>)<\/span>\r\n\r\n# Output:<\/span>\r\n# 'Key not found', lookup key was \"Random_Key\"<\/span>\r\n<\/code><\/pre>\nPrinting all of the properties<\/h2>\n
By utilizing the items() method, we can obtain a Tuple collection that comprises both keys and their corresponding PropertyTuple values.<\/p>\n
items_view =<\/span> configs.<\/span>items(<\/span>)<\/span>\r\nprint<\/span>(<\/span>type<\/span>(<\/span>items_view)<\/span>)<\/span>\r\n\r\nfor<\/span> item in<\/span> items_view:<\/span>\r\n print<\/span>(<\/span>item)<\/span>\r\n<\/code><\/pre>\nCan you provide just one alternative option for the following text in your native language:<\/p>\n
Result:<\/p>\n
<<\/span>class<\/span> 'collections.abc.ItemsView'<\/span>><\/span>\r\n(<\/span>'DB_HOST'<\/span>,<\/span> PropertyTuple(<\/span>data=<\/span>'localhost'<\/span>,<\/span> meta=<\/span>{<\/span>}<\/span>)<\/span>)<\/span>\r\n(<\/span>'DB_SCHEMA'<\/span>,<\/span> PropertyTuple(<\/span>data=<\/span>'Test'<\/span>,<\/span> meta=<\/span>{<\/span>}<\/span>)<\/span>)<\/span>\r\n(<\/span>'DB_User'<\/span>,<\/span> PropertyTuple(<\/span>data=<\/span>'root'<\/span>,<\/span> meta=<\/span>{<\/span>}<\/span>)<\/span>)<\/span>\r\n(<\/span>'DB_PWD'<\/span>,<\/span> PropertyTuple(<\/span>data=<\/span>'root@neon'<\/span>,<\/span> meta=<\/span>{<\/span>}<\/span>)<\/span>)<\/span>\r\n<\/code><\/pre>\nIn order to obtain the desired output of key=value, we can implement the following code.<\/p>\n
for<\/span> item in<\/span> items_view:<\/span>\r\n print<\/span>(<\/span>item[<\/span>0<\/span>]<\/span>,<\/span> '='<\/span>,<\/span> item[<\/span>1<\/span>]<\/span>.<\/span>data)<\/span>\r\n<\/code><\/pre>\nResult:<\/p>\n
DB_HOST =<\/span> localhost\r\nDB_SCHEMA =<\/span> Test\r\nDB_User =<\/span> root\r\nDB_PWD =<\/span> root@neon\r\n<\/code><\/pre>\nObtaining a collection of key entries from the properties file.<\/h2>\n
I have a full program that can read the properties file and generate a list containing all the keys.<\/p>\n
from<\/span> jproperties import<\/span> Properties\r\n\r\nconfigs =<\/span> Properties(<\/span>)<\/span>\r\n\r\nwith<\/span> open<\/span>(<\/span>'app-config.properties'<\/span>,<\/span> 'rb'<\/span>)<\/span> as<\/span> config_file:<\/span>\r\n configs.<\/span>load(<\/span>config_file)<\/span>\r\n\r\nitems_view =<\/span> configs.<\/span>items(<\/span>)<\/span>\r\nlist_keys =<\/span> [<\/span>]<\/span>\r\n\r\nfor<\/span> item in<\/span> items_view:<\/span>\r\n list_keys