我有一个这样的数据框
column_name
0 OnePlus phones never fail to meet my expectatiion.
1 received earlier than expected for local set.
2 \n
3 good
4 must buy!
5 \t
6
7 awesome product!
8 \n
我要删除其中仅包含\n
,\t
,
,\n
的所有行。
输出应如下所示:
column_name
0 OnePlus phones never fail to meet my expectatiion.
1 received earlier than expected for local set.
2 good
3 must buy!
4 awesome product!
我尝试了以下方法:
df = df[df.column_name != '\n'].reset_index(drop=True)
df = df[df.column_name != ''].reset_index(drop=True)
df = df[df.column_name != ' '].reset_index(drop=True)
df = df[df.column_name != ' '].reset_index(drop=True)
df = df[df.column_name != ' \n '].reset_index(drop=True)
但是有没有更多的优雅方式或pythonic方式来做到这一点,而不是重复执行代码?
答案 0 :(得分:3)
您可以使用Series.str.strip
并仅比较空字符串:
df1 = df[df.column_name.str.strip() != ''].reset_index(drop=True)
或将空值转换为布尔值:
df1 = df[df.column_name.str.strip().astype(bool)].reset_index(drop=True)
或者过滤词,对我来说strip
是必要的(也许应该删除真实数据strip
):
df1 = df[df.column_name.str.strip().str.contains('\W', na=False)].reset_index(drop=True)
如果需要删除丢失的值,并且没有字符串值将这些值替换为NaN
,然后使用DataFrame.dropna
:
df.column_name = df.column_name.replace(r'^\s*$', np.nan, regex=True)
df1 = df.dropna(subset=['column_name']).reset_index(drop=True)
答案 1 :(得分:2)
使用df.str.contains()检查正斜杠后是否有任何较小的字母
df[df.Column Name.str.contains('[\\][a-z]+',case=True, na=False, regex=True)]
在您的情况下,数据:
print(pd.DataFrame({'A':['OnePlus phones never fail to meet my expectatiion','received earlier than expected for local set.','\n','good','\t', np.nan,'must buy!','','awesome product!','\n' ]}))
A
0 OnePlus phones never fail to meet my expectatiion
1 received earlier than expected for local set.
2 \n
3 good
4 \t
5 NaN
6 must buy!
7
8 awesome product!
9 \n
解决方案
print(df[df.A.str.contains('[\\][a-z]+',case=True, na=False, regex=True)])
A
0 OnePlus phones never fail to meet my expectatiion
1 received earlier than expected for local set.
3 good
6 must buy!
8 awesome product!
答案 2 :(得分:1)
另一种方法,删除条目与标记元素匹配的行:
df = df[~df['column_name'].isin(['\\n','\\t'])].dropna()
如果最后一行(或其他行)中有多余的空格,则可以先执行以下操作:
df['column_name'] = df['column_name'].str.strip()