Python compile() Function
Python3 Built-in Functionscompile()It is a built-in function in Python used to compile source code into a code object.
The compiled code object can beexec()oreval()executed.compile()It is mainly used for code optimization, dynamic execution, and precompiling common code.
Glossary： compile 意为"编译"，将源代码转换为可执行代码。
Basic Syntax and Parameters
Syntax Format
compile(source, filename, mode, flags=0, dont_inherit=False, optimize=-1)
Parameter Description
- Parameter source：
- Type: string or AST object
- Description: The source code to compile.
- Type: string
- Description: The name of the code source, usually set to the source file name.
- Type: string
- Description: Compilation mode,
'exec'(statement block),'eval'(expression),'single'(single statement).
Function Description
- Return Value: Returns a code object.
Examples
Example 1: Basic Usage
Example
# Compile expression
code = compile("1 + 2", "<string>", "eval")
result = eval(code)
print(result) # Output: 3
# Compile statement block
code = compile("print('Hello')", "<string>", "exec")
exec(code) # Output: Hello
# Compile multi-line code
code = compile("""
x = 10
y = 20
result = x + y
""", "<string>", "exec")
exec(code)
print(result) # Output: 30
code = compile("1 + 2", "<string>", "eval")
result = eval(code)
print(result) # Output: 3
# Compile statement block
code = compile("print('Hello')", "<string>", "exec")
exec(code) # Output: Hello
# Compile multi-line code
code = compile("""
x = 10
y = 20
result = x + y
""", "<string>", "exec")
exec(code)
print(result) # Output: 30
Run result:
3 Hello 30
Code analysis:
- mode='eval' is used for a single expression.
- mode='exec' is used for statement blocks.
Example 2: Dynamic Code Execution
Example
# Code entered by the user
user_code = "for i in range(5): print(i, end=' ')"
code = compile(user_code, "<user>", "exec")
exec(code) # Output: 0 1 2 3 4
# Use compile to precompile for better performance
import time
code_str = "sum(range(1000))"
compiled = compile(code_str, "<string>", "eval")
start = time.time()
for _ in range(10000):
eval(compiled)
print(fAfter compilation: {time.time() - start:.4f} seconds)
user_code = "for i in range(5): print(i, end=' ')"
code = compile(user_code, "<user>", "exec")
exec(code) # Output: 0 1 2 3 4
# Use compile to precompile for better performance
import time
code_str = "sum(range(1000))"
compiled = compile(code_str, "<string>", "eval")
start = time.time()
for _ in range(10000):
eval(compiled)
print(fAfter compilation: {time.time() - start:.4f} seconds)
Run result:
compile() can precompile code to improve execution efficiency.
compile()It is very useful in scenarios of dynamic code generation and execution.
Other Extensions