[nslen + 2:] if elem.text is None or elem.text == 'NULL': continue node_dict[tag_name] = elem.text current_cfg = node_dict.get('current-cfg-file') if current_cfg is not None: current_cfg = os.path.basename(current_cfg) next_cfg = node_dict.get('next-cfg-file') if next...
Check if a string is null or empty in XSLT 242 TypeError: 'str' does not support the buffer interface 120 Using pickle.dump - TypeError: must be str, not bytes 316 What is the best way to convert byte array to string? 266 Converting string to byte array in C# 182 python 3.5: TypeEr...
最近在看《Effective Python》,里面提到判断字符串或者集合是否为空的原则,原文如下: Don’t check for empty values (like [] or '') by checking...意即,不要通过取字符串或者集合的长度来判断是否为空,而是要用not关键字来判断,因为当字符串或集合为...
df_sig_check['weight'] = df_sig_check['weight'].fillna(0) df_sig_check['rate'] = df_sig_check['rate'].fillna(0) print(rf"{datetime.now()}: 1000_500 昨天的信号和数据库对比相关度是: {round(1 - cosine(df_sig_check['rate'], df_sig_check['weight']), 4)}") print(rf"{da...
__init__在C中的具体实现函数为_io_StringIO___init___impl,签名如下: /*[clinic input] _io.StringIO.__init__ initial_value as value: object(c_default="NULL") = '' newline as newline_obj: object(c_default="NULL") = '\n' ...
Python语言比起C++、Java等主流语言,语法更简洁,也更接近英语,对编程世界的新人还是很友好的,这也是其显著优点。最近总有人问我Python相关的问题,这些问题也偏基础,自古有句话,授人以鱼不如授人以渔,刚好趁五一时间总结了几篇Python的知识点,帮助小伙伴成功入坑Python,将这门工具语言顺利掌握起来。 Python常用数据...
2. The null or empty set is a set with zero elements. 3. Sets are unordered. 4. Because [] creates an empty list, you might expect {} to create an empty set. Instead, {} creates an empty dictionary. That’s also why the interpreter prints an empty set as set() instead of {...
__defaults__ (['some_string', 'some_string'],) >>> some_func([]) >>> some_func.__defaults__ (['some_string', 'some_string'],) A common practice to avoid bugs due to mutable arguments is to assign None as the default value and later check if any value is passed to the ...
An empty variable typically signifies that it either has not been initialized with any data or has been explicitly set to a null state. If you consider variable is null only if it is None, you can go through check if variable is None in Python. 3. Using not Operator The most pythonic ...
StringDtype Timedelta TimedeltaIndex TimestampUInt16Dtype UInt32Dtype UInt64Dtype UInt64Index UInt8Dtypeapi array arrays bdate_range compatconcat core crosstab cut date_rangedescribe_option errors eval factorize get_dummiesget_option infer_freq interval_range io isnaisnull json_normalize lreshape melt ...