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How do I convert a string to the variable name in Python?
For example, if the program contains a object named self.post that contains a variable named, I want to do something like:
somefunction("self.post.id") = |Value of self.post.id| 
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String Into Variable Name in Python Using the vars() Function. Instead of using the locals() and the globals() function to convert a string to a variable name in python, we can also use the vars() function. The vars() function, when executed in the global scope, behaves just like the globals() function.
How to create a string and assign it to a variable. To create a string, put the sequence of characters inside either single quotes, double quotes, or triple quotes and then assign it to a variable.
Declaring strings as variables can make it easier for us to work with strings throughout our Python programs. To store a string inside a variable, we need to assign a variable to a string. In this case let's declare my_str as our variable: my_str = "Sammy likes declaring strings."
Strings can be converted to lists using list() .
Note: do not use eval in any case where you are getting the name to look up from user entered input. For example, if this comes from a web page, there is nothing preventing anyone from entering:
__import__("os").system("Some nasty command like rm -rf /*") as the argument. Better is to limit to well-defined lookup locations such as a dictionary or instance using getattr(). For example, to find the "post" value on self, use:
varname = "post" value = getattr(self, varname) # Gets self.post Similarly to set it, use setattr():
value = setattr(self, varname, new_value) To handle fully qualified names, like "post.id", you could use something like the below functions in place of getattr() / setattr().
def getattr_qualified(obj, name): for attr in name.split("."): obj = getattr(obj, attr) return obj def setattr_qualified(obj, name, value): parts = name.split(".") for attr in parts[:-1]: obj = getattr(obj, attr) setattr(obj, parts[-1], value) As referenced in Stack Overflow question Inplace substitution from ConfigParser, you're looking for eval():
print eval('self.post.id') # Prints the value of self.post.id If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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