熊猫。concat方法怎么在Python3中使用?很多新手对此不是很清楚,为了帮助大家解决这个难题,下面小编将为大家详细讲解,有这方面需求的人可以来学习下,希望你能有所收获。
python可以做什么
python是一种编程语言,内置了许多有效的工具,python几乎无所不能,该语言通俗易懂,容易入门,功能强大,在许多领域中都有广泛的应用,例如最热门的大数据分析,人工智能,网页开发等。
熊猫。合并参数列表如下图,其中只有obj是必须得参数,另外常用参数包括obj,轴,加入,钥匙,ignore_index。
import pandas as pd import numpy  as np , #定义资料集 df1 =, pd.DataFrame (np.ones((3, 4)) * 0,,列=[& # 39;一个# 39;& # 39;b # 39;, & # 39; c # 39;, & # 39; d # 39;]) df2 =, pd.DataFrame (np.ones((3, 4)) * 1,列=[& # 39;一个# 39;& # 39;b # 39;, & # 39; c # 39;, & # 39; d # 39;]) df3 =, pd.DataFrame (np.ones((3, 4)) * 2,列=[& # 39;一个# 39;& # 39;b # 39;, & # 39; c # 39;, & # 39; d # 39;]), # concat纵向合并 时间=res pd.concat ([df1, df2,, df3],,轴=0) , #打印结果 打印(res) & # 39;& # 39;& # 39; ,a b  c d 0,0.0,0.0,0.0,0.0 1,0.0,0.0,0.0,0.0 2,0.0,0.0,0.0,0.0 0,1.0,1.0,1.0,1.0 1,1.0,1.0,1.0,1.0 2,1.0,1.0,1.0,1.0 0,2.0,2.0,2.0,2.0 1,2.0,2.0,2.0,2.0 2,2.0,2.0,2.0,2.0 & # 39;& # 39;& # 39;
上述指数为0,1,2,0,1,2形式。为什么会出现这样的情况,其实是仍然按照合并前的指数组合起来的。若希望递增,请看下面示例:
ignore_index(重置指数)
重置后的指数为0,1,……8
res =, pd.concat ([df1, df2,, df3],,=0,轴,ignore_index=True) #,将ignore_index设置为True 打印(res), #打印结果 & # 39;& # 39;& # 39; ,a b  c d 0,0.0,0.0,0.0,0.0 1,0.0,0.0,0.0,0.0 2,0.0,0.0,0.0,0.0 3,1.0,1.0,1.0,1.0 4,1.0,1.0,1.0,1.0 5,1.0,1.0,1.0,1.0 6,2.0,2.0,2.0,2.0 7,2.0,2.0,2.0,2.0 8,2.0,2.0,2.0,2.0 & # 39;& # 39;& # 39;
加入(合并方式)
加入=& # 39;外# 39;为预设值,因此未设定任何参数时,函数默认加入=& # 39;外# 39;。此方式是依照列来做纵向合,并有相同的列上下合并在一起,其他独自的列个自成列,原本没有值的位置皆以NaN填充。
import pandas as pd import numpy  as np , #定义资料集 df1 =, pd.DataFrame (np.ones((3, 4)) * 0,,列=[& # 39;一个# 39;& # 39;b # 39;, & # 39; c # 39;, & # 39; d # 39;],,指数=[1,2,3]) df2 =, pd.DataFrame (np.ones((3, 4)) * 1,列=[& # 39;b # 39; & # 39; c # 39;, & # 39; d # 39;, & # 39; e # 39;],,指数=(2、3、4)), 时间=res pd.concat ([df1, df2],,轴=0,,加入=& # 39;外# 39;),#纵向“外“合并df1与df2 , 打印(res) & # 39;& # 39;& # 39; ,a b  c d e ,1,0.0,0.0,0.0,0.0,NaN ,2,0.0,0.0,0.0,0.0,NaN ,3,0.0,0.0,0.0,0.0,NaN ,2 NaN 1.0, 1.0, 1.0, 1.0 ,3 NaN 1.0, 1.0, 1.0, 1.0 ,4 NaN 1.0, 1.0, 1.0, 1.0 & # 39;& # 39;& # 39; 时间=res pd.concat ([df1, df2],,轴=0,,加入=& # 39;内部# 39;),#纵向“内“合并df1与df2 , #打印结果 打印(res) & # 39;& # 39;& # 39; b c d ,1,0.0,0.0,0.0 ,2,0.0,0.0,0.0 ,3,0.0,0.0,0.0 ,2,1.0,1.0,1.0 ,3,1.0,1.0,1.0 ,4,1.0,1.0,1.0 & # 39;& # 39;& # 39;pandas.concat方法怎么在Python3中使用