defcheck_variable(variable_name):ifvariable_nameinglobals()orvariable_nameinlocals():print(f"The variable{variable_name}exists.")else:print(f"The variable{variable_name}does not exist.")x=10check_variable("x")# 输出:The variable x exists.y=5check_variable("y")# 输出:The variable y exis...
To check if a local variable exists or not, we can use the built-in locals() function. Example: def name(): a = "Hello" # a is a local variable if 'a' in locals(): print ('a variable exist') else: print ('a variable does not exist') name() Output: "a variable exist" ...
' if the file exists, 'The file does not exist.' otherwise. Python Copy In this example, we first import theosmodule. We then define a variablefile_paththat holds the name of the file we want to check. We pass this variable to theos.path.exists()function inside anifstatement. If the...
file_exist(file_path=''): """ 判断主控板上某文件是否存在 """ if file_path is None or file_path == '': logging.warning("The path of file is none or ''.") return ERR if file_path.lower().startswith('flash'): return file_exist_on_master(file_path) else: return file_exist_...
18.UnboundLocalError: local variable 'x' referenced before assignment 试图访问一个不存在的本地变量。 x = 1 def foo(): x = x + 1 # x在foo()这个范围内并没有提前赋值,相当于还不存在。 print(x) foo() 如何修改:可以将外面的变量传入函数。
The somewhat cryptic output means that the first variable refers to the local first_child() function inside of parent(), while second points to second_child().You can now use first and second as if they’re regular functions, even though you can’t directly access the functions they point...
Listing2-1Notice howtext(i.e., “My favorite beasts”)can be displayed next to a variable using a comma in Python 在清单 2-1 中,我们首先定义了一个变量,Fine_Animals,,这是一个适合我们目的的名字。然后我们继续使用 print 命令输出它的内容。这个输出应该是说我最喜欢的野兽:{ '蝙蝠','猫','...
First, we will find the length of the input string using thelen()function. We will store the length in a variablestr_len. Now, we will check if the length of the input string is 0. If the length of the input string is 0, we will say that the string is an empty string. Otherwise...
Alternately, you can use a custom environment variable that's defined on each platform to contain the full path to the Python interpreter to use, so that no other folder paths are needed. If you need to pass arguments to the Python interpreter, you can use thepythonArgsproperty. ...
Check if there is __init.py__ under /a How to fix NameError: name 'var' is not defined when define var in try statement and use it in catch / finally statement ? Declare the var before try statement with var = None python - Using a variable in a try,catch,finally statement with...