如何迭代行并附加列名

Question

我有一个数据框（csv 文件），它看起来像：

Name   Apple  Banana  Carrot Mango

Adam   false   false  true   true
James  false   true   true   false
Jessie false   false  true   true

我需要遍历行并在字符串中附加带有 'true' 值的列名称，输出如下：

Carrot,Mango
Banana,Carrot
Carrot,Mango

以下是我的尝试（无效）：

data = pandas.read_csv("filename.csv")
df = pandas.DataFrame(data)
columns = df.columns.values
str = ""
for index, row in df.iterrows():
    for c in columns:
        if c == True:
            str.append(c)

Answer 1

我不知道你真的需要 pandas 这个

with open("my.csv") as f:
    headers = next(f).split(",")[1:]
    lines = (line for line in f if line.strip())        
    for line in lines:
        for hdr,itm in zip(headers,line.split(",")[1:]:
           if "true" in itm:
               print hdr

Answer 2

这是使用 Pandas 的解决方案。

In [1]: import pandas as pd

In [2]: data = pd.DataFrame({"Apple": [False, False, False], "Banana": [False, True, False], "Carrot": [True, True, True], "Mango": [True, False, True]}, columns=["Apple", "Banana", "Carrot", "Mango"])

In [3]: true_columns = []

In [4]: for index, row in data.iterrows():
   ...:     true_col_list = [col for col in data.columns if row[col]]
   ...:     true_columns.append(",".join(true_col_list))
   ...:

In [5]: data["true_columns"] = true_columns

In [6]: data
Out[6]:
   Apple Banana Carrot  Mango   true_columns
0  False  False   True   True   Carrot,Mango
1  False   True   True  False  Banana,Carrot
2  False  False   True   True   Carrot,Mango

如何迭代行并附加列名

how to iterate rows and append column name

python

dataframe

pandas