如何根据列上的特定值将单行插入数据框

Question

我想将“像素”数据框中存在的行添加到“ with_key”数据框中，其中with_key [“ Key”]列中单元格的值等于“ 2”

pixels = pd.DataFrame()
with_key = pd.DataFrame(columns=["Key"])

keys = []

for x in range(5):
    key = x
    keys.append(key)
with_key["Key"] = keys
print(with_key)

arr=np.array([0,0,0,0,0,255,0,0,0])

pixels = pd.DataFrame(arr)
pixels = pixels.T

pixels.head()

Answer 1

这是语法

import pandas as pd
with_key = pd.DataFrame(columns=["Key"])

keys = []


for x in range(5):
    key = x
    keys.append(key)
# with_key["Key"] = keys
for key in keys:
    if key == 1:
        with_key = with_key.append({'Key': key}, ignore_index=True)

print(with_key)

您可以参考熊猫append文档here，其中提供了有关如何在现有数据框中插入行的示例