173. Dynamic Importing of Modules

Snippet 1: Basic Dynamic Import

import importlib

module_name = "math"
math_module = importlib.import_module(module_name)
print(math_module.sqrt(16))  # Output: 4.0

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Snippet 2: Importing a Specific Function

import importlib

module_name = "math"
function_name = "pow"

math_module = importlib.import_module(module_name)
power_function = getattr(math_module, function_name)
print(power_function(2, 3))  # Output: 8.0

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Snippet 3: Importing a Module from a Custom Path

import importlib.util

module_path = "/path/to/custom_module.py"
module_name = "custom_module"

spec = importlib.util.spec_from_file_location(module_name, module_path)
custom_module = importlib.util.module_from_spec(spec)
spec.loader.exec_module(custom_module)

# Assuming the module has a function `greet`
print(custom_module.greet())

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Snippet 4: Dynamic Import Based on User Input

import importlib

module_name = input("Enter the module name: ")  # Example: 'os'
try:
    module = importlib.import_module(module_name)
    print(f"Module '{module_name}' imported successfully.")
except ModuleNotFoundError:
    print(f"Module '{module_name}' not found.")

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Snippet 5: Listing Attributes of a Dynamically Imported Module

import importlib

module_name = "math"
math_module = importlib.import_module(module_name)
print(dir(math_module))

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Snippet 6: Reimporting a Module

import importlib

module_name = "math"
math_module = importlib.import_module(module_name)
print(math_module.sqrt(16))  # First import

# Reimport the module
math_module = importlib.reload(math_module)
print(math_module.sqrt(25))  # After reload

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Snippet 7: Dynamically Importing Submodules

import importlib

module_name = "os.path"
path_module = importlib.import_module(module_name)
print(path_module.join("folder", "file.txt"))  # Output: folder/file.txt (depends on OS)

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Snippet 8: Importing Classes Dynamically

import importlib

module_name = "collections"
class_name = "Counter"

collections_module = importlib.import_module(module_name)
Counter = getattr(collections_module, class_name)
counter = Counter("aabbcc")
print(counter)  # Output: Counter({'a': 2, 'b': 2, 'c': 2})

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Snippet 9: Dynamic Import with Exception Handling

import importlib

module_name = "nonexistent_module"

try:
    module = importlib.import_module(module_name)
    print(f"Module '{module_name}' imported successfully.")
except ModuleNotFoundError as e:
    print(f"Error: {e}")

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Snippet 10: Dynamically Importing a Function and Calling It

import importlib

module_name = "random"
function_name = "randint"

random_module = importlib.import_module(module_name)
randint_function = getattr(random_module, function_name)
print(randint_function(1, 10))  # Output: Random integer between 1 and 10

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