In[37]: tup = ('foo','bar','baz')In[38]: b_list =list(tup)In[39]: b_listOut[39]: ['foo','bar','baz'] list函数常用来在数据处理中实体化迭代器或生成器: 深色代码主题 复制 In[42]: gen =range(10)In[43]: genOut[43]:range(0,10)In[44]:list(gen)Out[44]: [0,1,2,3...
prices_data = np.random.rand(len(date_range), len(stock_symbols)) * 100 # 随机价格 prices = pd.DataFrame(prices_data, index=date_range, columns=stock_symbols) # 为相同的4只股票生成随机交易量,但日期范围是s1的子集 subset_dates = date_range[::2] # 使用每隔两天的日期作为s2的子集 volumes...
DataFrame.drop_duplicates(subset=None, keep='first', inplace=False) subset : column label or sequence of labels, optional 用来指定特定的列,默认所有列 keep : {‘first’, ‘last’, False}, default ‘first’ 删除重复项并保留第一次出现的项 inplace : boolean, default False 是直接在原来数据上...
1#graphics.py2"""Simple object oriented graphics library3The library is designed to make it very easy for novice programmers to4experiment with computer graphics in an object oriented fashion. It is5written by John Zelle for use with the book "Python Programming: An6Introduction to Computer Scie...
df_subset=df.iloc[0:5,[1,2]] 根据条件创建数据屏蔽:创建布尔屏蔽以过滤数据。 mask=(df['column']>10)&(df['column']<20)df_masked=df[mask] 时间序列的扩展和滚动操作:使用扩展或滚动操作进行累积计算。 df_expanding=df['data_column'].expanding().mean()df_rolling=df['data_column'].rolling...
loc和iloc可以认为类似于Python列表切片。为了进一步说明这一点,让我们选择多行。您将如何处理清单? 在Python中,只需用方括号进行切片,例如example_list [1:4]。在熊猫中,其工作方式相同: movie_subset = movies_df.loc['Prometheus':'Sing']movie_subset = movies_df.iloc[1:4]movie_subset ...
...iflen(target)>1:sub=target[1]myclass="%sCLI"%sub.capitalize()eliftarget[0]=='ansible':sub='adhoc'myclass='AdHocCLI'else:raiseAnsibleError("Unknown Ansible alias: %s"%me)try:mycli=getattr(__import__("ansible.cli.%s"%sub,fromlist=[myclass]),myclass)...cli=mycli(args)exit_cod...
()],right_on=['交易日期'],how='left')df.drop_duplicates(subset=['交易日期'],keep='first',inplace=True)mom_col_list=[xforxindf.columns.tolist()if'_mom'inx]# 风格变化条件df['style']=df[mom_col_list].apply(lambdarow:self.cal_style(row),axis=1)df['style'].fillna(method='...
Let’s start with the following simple list of movie titles and work up from there: Here’s the same list written in a way that Python understands: To turn the human-friendly list into a Python-friendly one, follow this four-step process: Convert each of the names into strings by surrou...
you use gather() function to run several functions # concurrently but we actually modify the data and we rely on the order of functions for func in [ create, read, update, delete, joins, filter_and_sort, subset_of_columns, pagination, aggregations, raw_data, ]: print(f"Executing: {...