读取文件

读取excel文件

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import pandas as pd
df = pd.read_excel(file_path, sheet_name)

读取csv文件

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import pandas as pd
df = pd.read_csv(file_path)

写入文件

创建一个DataFrame对象，设置列名，data可为二维数组

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df = pd.DataFrame(data=None, columns = ["disease", "relation", "object"])

写入文件

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df.to_csv(file_path, index = False, sep=",")

循环迭代数据

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for row in range(df.shape[0]):
  data = df.loc[row, "Month_No"]

插入整列数据

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import pandas as pd
s = pd.Series([6,8,3,1,12])
df = pd.DataFrame(s,columns=['Month_No'])
df.insert(1,"No_of_days",[30,31,31,31,31],True)# 插入列
df
Month_No No_of_days
0 6 30
1 8 31
2 3 31
3 1 31
4 12 31

尾部插入数据

append插入

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df = df.append({"Month_No":7,"No_of_days":31},ignore_index=True)
df

concat插入

append方法已经废弃，推荐使用concat方法

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df_tmp=pd.DataFrame([[7,31],[4,30]], columns=["Month_No", "No_of_days"])
df = pd.concat([df, df_tmp], ignore_index = True)
df
Month_No No_of_days
0 6 30
1 8 31
2 3 31
3 1 31
4 12 31
5 7 31
6 4 30

修改列名

暴力修改

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df.columns=['MonthNo','NoOfDays']  
df
MonthNo NoOfDays
0 6 30
1 8 31
2 3 31
3 1 31
4 12 31

利用rename修改

注意：inplace参数不能省略

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df.rename(columns={'MonthNo':'Month_No','NoOfDays':'No_of_days'},inplace=True) 
df
Month_No No_of_days
0 6 30
1 8 31
2 3 31
3 1 31
4 12 31

删除列数据

df.drop()
axis=1: 删除列

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feature_1 = df_feature_all.drop(labels=["structure of ionizable lipid (SMILE)","IgG"],axis=1).to_numpy()

Reference

  1. pandas尾部追加行记录append