将数据追加到Pandas gloabl dataframe变量不存在

与 list.append , pandas.DataFrame.append 是 不 就地操作。稍微修改一下代码就可以了:

import pandas as pd

df = pd.DataFrame()

def my_func():
    global df
    d = pd.DataFrame()
    for i in range(10):
        dct = {
            "col1": i,
            "col2": 'value {}'.format(i)}
        d = d.append(dct, ignore_index=True) # <<< Assignment needed
        # df.append(dct, ignore_index=True) # Does not seem to append anything to the global variable
    df = d # does not assign any values to the global variable

my_func()

df.head()

输出:

   col1     col2
0   0.0  value 0
1   1.0  value 1
2   2.0  value 2
3   3.0  value 3
4   4.0  value 4