python提示dataframe has no attribute 'shape'的错误

import rpy2.robjects as robjects

df1.to_csv('df1.csv', encoding='utf-8',index=False)
r_statement = """
                library('lavaan')
                dat <- read.csv('df1.csv')
            """
robjects.r(r_statement)

运行上面的代码时，会提示：dataframe has no attribute 'shape'的错误，请问各位大神，怎么解决？在r语言里运行read.csv('df1.csv')就不会提示错误，为什么放到python里就不行了？

最好把错误截个图。

代码不完整

dataframe.value.shape()