[python]数据合并concat

Numpy 的concat

arr1 = np.random.randint(0, 10, (3, 4))
arr2 = np.random.randint(0, 10, (3, 4))

np.concatenate([arr1, arr2])
np.concatenate([arr1, arr2], axis=1)#按照列

Series 的concat

# index 没有重复的情况
ser_obj1 = pd.Series(np.random.randint(0, 10, 5), index=range(0,5))
ser_obj2 = pd.Series(np.random.randint(0, 10, 4), index=range(5,9))
ser_obj3 = pd.Series(np.random.randint(0, 10, 3), index=range(9,12))
pd.concat([ser_obj1, ser_obj2, ser_obj3])

# index 有重复的情况
ser_obj1 = pd.Series(np.random.randint(0, 10, 5), index=range(5))
ser_obj2 = pd.Series(np.random.randint(0, 10, 4), index=range(4))
ser_obj3 = pd.Series(np.random.randint(0, 10, 3), index=range(3))
pd.concat([ser_obj1, ser_obj2, ser_obj3], axis=1, join='inner')

DataFrame上的concat

df_obj1 = pd.DataFrame(np.random.randint(0, 10, (3, 2)), index=['a', 'b', 'c'],
                       columns=['A', 'B'])
df_obj2 = pd.DataFrame(np.random.randint(0, 10, (2, 2)), index=['a', 'b'],
                       columns=['C', 'D'])

pd.concat([df_obj1, df_obj2])