'hello',1997,2000)After deleting tup:---------------------------------------------------------------------------NameErrorTraceback(most recent call last)<ipython-input-1-a12bbf13863f>in<module>()4del tup5print("
代码语言:javascript 代码运行次数:0 运行 AI代码解释 >>> del info['city'] #删除已经不存在的key,会报错 Traceback (most recent call last): File "<stdin>", line 1, in <module> KeyError: 'city' info.clear()删除字典的全部元素 代码语言:javascript 代码运行次数:0 运行 AI代码解释 >>> info....
Series.dt.is_year_start Indicate whether the date is the first day of a year. Series.dt.is_year_end Indicate whether the date is the last day of the year. Series.dt.is_leap_year Boolean indicator if the date belongs to a leap year. Series.dt.days_in_month The number of days in ...
3. Iterate a list 我们可以使用来遍历列表项for loop。 charList = ["a", "b", "c"] for x in charList: print(x) # a # b # c 4. Check if a item exists in the list 使用'in'关键字确定列表中是否存在指定的项目。 charList = ["a", "b", "c"] if "a" in charList: print("a...
# 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 ...
item_stream =["apple","orange","apple","banana","orange","apple","grape"] item_counts =defaultdict(int)# 如果键不存在,默认创建一个整数 0 foriteminitem_stream: # 如果 item 是新键,item_counts[item] 会自动变为 0,然后 +1 item_counts[item]+=1 ...
mask) result = pd.DataFrame( {'start_time': times[:-1], 'time_inbetween': np.d...
Lists#列表 Lists are another type of object in Python. They are used to store an indexed list of items.A list is created using square brackets with commas separating items.The certain item in the list can be accessed by using its index in square bracke
老Python带你从浅入深探究List 列表 Python中的列表(list)是最常用的数据类型之一。 Python中的列表可以存储任意类型的数据,这与其他语言中的数组(array)不同。 被存入列表中的内容可称之为元素(element)或者数据项(data item)亦或是值(value)。 虽然Python列表支持存储任意类型的数据项,但不建议这么做,事实上...
charList.pop()# removes'd'- last itemprint(charList) # ['a','b','c'] charList.pop(1)# removes'b'print(charList) # ['a','c'] 7.3. clear() 它清空列表。 charList = ["a","b","c","d"] charList.clear()print(charList)# [] ...