Python和Pandas:构造lambda参数

我正在用Python和Pandas编写一个脚本,它使用lambda语句根据分配给每行的数字等级在csv列中编写预格式化的注释。虽然我能在很多系列中做到这一点,但我在一个案例中遇到了困难。

以下是csv的结构:

下面是编写新专栏的工作代码 composition_comment (我相信有一种方法可以更简洁地表达这一点,但我仍在学习Python和Pandas。)

import pandas as pd

df = pd.read_csv('stack.csv')
composition_score_value = 40  #calculated by another process

composition_comment_a_level = "Good work." # For scores falling between 100 and 90 percent of composition_score_value.
composition_comment_b_level = "Satisfactory work." # For scores between 89 and 80.
composition_comment_c_level = "Improvement needed." # For scores between 79 and 70.
composition_comment_d_level = "Unsatisfactory work." # For scores below 69.

df['composition_comment'] = df['composition_score'].apply(lambda element: composition_comment_a_level if element <= (composition_score_value * 1) else element >= (composition_score_value *.90))
df['composition_comment'] = df['composition_score'].apply(lambda element: composition_comment_b_level if element <= (composition_score_value *.899) else element >= (composition_score_value *.80))
df['composition_comment'] = df['composition_score'].apply(lambda element: composition_comment_c_level if element <= (composition_score_value *.799) else element >= (composition_score_value *.70))
df['composition_comment'] = df['composition_score'].apply(lambda element: composition_comment_d_level if element <= (composition_score_value *.699) else element >= (composition_score_value *.001))

df 

df.to_csv('stack.csv', index=False)

预期产出为:

但实际产出是:

你知道为什么会这样吗 True 正在写入的值,以及为什么最后一行处理正确?感谢您的帮助。