python ndarray与pandas series相互转换，ndarray与dataframe相互转换

array([[1],
       [2],
       [3]])

import numpy as np
import pandas as pd

data = np.array([1, 2, 3]).reshape(3, 1)
data_list = map(lambda x: x[0], data)
ser = pd.Series(data_list)

import numpy as np
import pandas as pd

data = np.array([1, 2, 3])
ser = pd.Series(data.tolist())

import pandas as pd

data = [['2019/08/01', 10],
        ['2019/08/01', 11]]
result = pd.DataFrame(data, columns=['ds', 'val'])
result['val'].values

data2 = pd.Series([1, 2, 3])
data2.values

import numpy as np
import pandas as pd

data = np.array([['2019/08/02', 'zhansan', 1], ['2019/08/03', 'lisi', 2], ['2019/08/04', 'wangwu', 3]])
df = pd.DataFrame(data)

import numpy as np
import pandas as pd

data = np.array([['', 'Col1', 'Col2'], ['Row1', 1, 2], ['Row2', 3, 4]])
df = pd.DataFrame(data=data[1:, 1:],  # 从第2行开始并且第2列开始作为数据
                  index=data[1:, 0],  # 第1列做索引，从第2行开始
                  columns=data[0, 1:])  # 第1行作为列名，从第2列开始

import pandas as pd

data = [['2019/08/01', 10],
        ['2019/08/01', 11]]
result = pd.DataFrame(data, columns=['ds', 'val'])
result.values

import pandas as pd

data = [['2019/08/01', 10],
        ['2019/08/01', 11]]
result = pd.DataFrame(data, columns=['ds', 'val'])
rs = result.values
print(rs[:, 0])
print(rs[0, :])

rs[:, 0] 逗号前面表示：行都保留，逗号后面0表示保留第一列，结果为['2019/08/01' '2019/08/01']

rs[0, :]表示保留第一行，列都保留，结果为['2019/08/01' 10]