The index method can’t return a number because the substring isn’t there, so we get a value error instead: In order to avoid thisTraceback Error, we can use the keywordinto check if a substring is contained in a string. In the case of Loops, it was used for iteration, whereas in...
input_file = args.INPUT_FILE output_file = args.OUTPUT_FILEifargs.hash: ha = args.hash_algorithmprint("File hashing enabled with {} algorithm".format(ha))ifnotargs.log:print("Log file not defined. Will write to stdout") 当组合成一个脚本并在命令行中使用-h参数执行时,上述代码将提供以下...
# Define a function named 'test_range' that checks if a number 'n' is within a specified range. # The range is determined by 'start_num' and 'end_num' (with 'end_num' having a default value of 0) def test_range(n, start_num, end_num=0): # Check if 'end_num' is greater ...
0.99,100)forlambda_reginlambda_reg_values:#For each value of lambda, compute build model and compute performance for lambda_reg in lambda_reg_values:X_train = np.column_stack([np.power(x_train,i)foriinrange(0,degree)])
我们经常做单元测试使用的机制 if __name__ == '__main__' ,表明作为主程序运行的Python 源文件可以被视为名为 __main__ 的 module,当然以 import py 方式加载,则__name__ 不会为 __main__。在初始化 __main__ module 时会将('__builtins__', __builtin__ module)插入到其 dict 中。也就...
# to get iterator from range function x = range(10) iter(x) x.__iter__() Map returns an interator from a list y = map(lambda i: i ** 2, list) decorator装饰器 装饰器是把一个要执行的函数包含在wrapper函数里面,并且在要执行的函数前后去执行代码 ...
start() check.start() 十二 条件Condition(了解) 使得线程等待,只有满足某条件时,才释放n个线程 import threading def run(n): con.acquire() con.wait() print("run the thread: %s" %n) con.release() if __name__ == '__main__': con = threading.Condition() for i in range(10): t =...
importsysdefbar(i):ifi ==1:raiseKeyError(1)ifi ==2:raiseValueError(2)defgood(): exception =Nonetry: bar(int(sys.argv[1]))exceptKeyErrorase: exception = eprint('key error')exceptValueErrorase: exception = eprint('value error')print(exception) good() ...
print("The value is: %i" % i) sum += i print("The new sum is: %i" % sum) # else if (可选,可以没有,也可以是多个elif分支) elif i==0: print("The sum did not change: %i" % sum) # 最后的else分支(可选)。 else:
wraps(func) def wrapper_repeat(*args, **kwargs): for _ in range(num_times): value = func(*args, **kwargs) return value return wrapper_repeat if _func is None: return decorator_repeat else: return decorator_repeat(_func) Compare this with the original @repeat. The only changes are ...