What is a symbol table in Python?

What is a symbol table in Python?

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Python symbol table example

I apologize for the misunderstanding earlier! Here's an example of a Python symbol table:

A symbol table is a data structure that keeps track of variables, functions, and labels within a program. In the context of Python, the symbol table is used by the interpreter to resolve identifiers (names) to their corresponding values or definitions.

Here's an example of how you could create a simple symbol table in Python:

class SymbolTable:
def init(self):
self.table = {}
def put(self, name, value):
self.table[name] = value
def get(self, name):
return self.table.get(name)
def contains(self, name):
return name in self.table
Example usage
table = SymbolTable()
Create some variables and functions
table.put("x", 5)
table.put("y", 10)
def add(a, b):
return a + b
Define some labels
table.put("label1", "Hello")
table.put("label2", "World")
Accessing the symbol table
print(table.get("x"))  # Output: 5
print(add(3, 4))  # Output: 7
Checking if a symbol exists
print(table.contains("y"))  # Output: True
print(table.contains("z"))  # Output: False
Iterating over the symbol table
for name, value in table.table.items():
print(f"{name}: {value}")

In this example, we define a SymbolTable class that has methods for putting (adding) and getting values from the symbol table. We also have a method to check if a symbol exists in the table.

The symbol table is initialized as an empty dictionary (self.table = {}). The put method adds a new key-value pair to the dictionary, while the get method returns the value associated with a given key (if it exists). The contains method checks if a given key exists in the dictionary.

In the example usage, we create some variables and functions, define some labels, and access the symbol table using the get and contains methods. We also iterate over the symbol table using a for loop to print out all the key-value pairs.

This is a very basic implementation of a symbol table, and in real-world scenarios you would likely want to add more features, such as handling scope and visibility rules, or supporting nested scopes. However, this should give you an idea of how a simple symbol table could be implemented in Python!