将 Pandas 数据框中的一些列转换为列表列表

Question

我有一个dataframe. 我想将一些数据转换为列表列表。我感兴趣的列是index，Name和Births。我的代码有效，但似乎效率低下，并且出于某种原因将字母 L 添加到每个索引的末尾。

我的代码：

import pandas as pd


data = [['Bob', 968, 'Male'], ['Jessica', 341, 'Female'], ['Mary', 77, 'Female'], ['John', 578, 'Male'], ['Mel', 434, 'Female']]
headers = ['Names', 'Births', 'Gender']
df = pd.DataFrame(data = data, columns=headers)
indexes = df.index.values.tolist()
mylist =  [[x] for x in indexes]

for x in mylist:
    x.extend([df.ix[x[0],'Names'], df.ix[x[0],'Births']])

print mylist

期望输出：

[[0, 'Bob', 968], [1, 'Jessica', 341], [2, 'Mary', 77], [3, 'John', 578], [4, 'Mel', 434]]

Answer 1

为什么不直接使用.values.tolist()你提到的？

import pandas as pd

# your data
# =================================================
data = [['Bob', 968, 'Male'], ['Jessica', 341, 'Female'], ['Mary', 77, 'Female'], ['John', 578, 'Male'], ['Mel', 434, 'Female']]
headers = ['Names', 'Births', 'Gender']
df = pd.DataFrame(data = data, columns=headers)

# nested list
# ============================
df.reset_index()[['index', 'Names', 'Births']].values.tolist()

Out[46]: 
[[0, 'Bob', 968],
 [1, 'Jessica', 341],
 [2, 'Mary', 77],
 [3, 'John', 578],
 [4, 'Mel', 434]]