Python 基于条件在dataframe内的列之间交换多个dataframe的行
我有一个数据框,如下所示Python 基于条件在dataframe内的列之间交换多个dataframe的行,python,pandas,numpy,if-statement,Python,Pandas,Numpy,If Statement,我有一个数据框,如下所示 foo = pd.DataFrame( [['chr1',2,1,'+',0.1,'NA','TSS1'], ['chr2',3,4,'-',0.03,'NA','TSS2'], ['chr3',7,6,'+',0.7,'NA','TSS3']], columns = ('CHR', 'start', 'end','Strand','Peak','Ratio','Annotation') ) fo
foo = pd.DataFrame(
[['chr1',2,1,'+',0.1,'NA','TSS1'],
['chr2',3,4,'-',0.03,'NA','TSS2'],
['chr3',7,6,'+',0.7,'NA','TSS3']],
columns = ('CHR', 'start', 'end','Strand','Peak','Ratio','Annotation')
)
foo
CHR start end Strand Peak Ratio Annotation
0 chr1 2 1 + 0.10 NA TSS1
1 chr2 3 4 - 0.03 NA TSS2
2 chr3 7 6 + 0.70 NA TSS3
我的目标是在列的开始和结束之间交换,即如果列的开始大于列的结束,那么我需要它交换它的位置,并保持列的其余部分完好无损或保持原样
像这样的,
def fun(x):
if df['start']> df['End']
print df[['CHR','end','start','Strand','Peak','Ratio','Annotation']]
else
return df
上面的函数不能按我的需要工作。
最后,我需要一个数据帧
CHR start end Strand Peak Ratio Annotation
0 chr1 1 2 + 0.10 NA TSS1
1 chr2 3 4 - 0.03 NA TSS2
2 chr3 6 7 + 0.70 NA TSS3
任何帮助或更好的建议都会很好。此外,我有大量的多数据帧。我认为更简单的是:
foo[['start','end']] = foo[['start','end']].apply(np.sort, axis=1)
print (foo)
CHR start end Strand Peak Ratio Annotation
0 chr1 1 2 + 0.10 NA TSS1
1 chr2 3 4 - 0.03 NA TSS2
2 chr3 6 7 + 0.70 NA TSS3
另一种具有min
和max
的解决方案:
df1 = foo[['start','end']]
foo['start'] = df1.min(axis=1)
foo['end'] = df1.max(axis=1)
print (foo)
CHR start end Strand Peak Ratio Annotation
0 chr1 1 2 + 0.10 NA TSS1
1 chr2 3 4 - 0.03 NA TSS2
2 chr3 6 7 + 0.70 NA TSS3
具有条件和,但需要为每列重复掩码
的解决方案:
b = foo['start'] < foo['end']
foo[['start','end']] = np.where(np.column_stack([b,b]),
foo[['start','end']],
foo[['end','start']])
print (foo)
CHR start end Strand Peak Ratio Annotation
0 chr1 1 2 + 0.10 NA TSS1
1 chr2 3 4 - 0.03 NA TSS2
2 chr3 6 7 + 0.70 NA TSS3
不,交换应该基于一个条件,而不仅仅是改变列的位置。如果列“end”小于列“start”,则交换这些行,否则保持原样。另外,上面的命令不适用于更大的dataframesAlso是否可以将其作为一个函数,我可以将其用于df.apply(func)Hmmm,我认为这是可能的,但不是那么容易。但给我一些时间。实际上没有问题,它为列ENDHMM抛出键错误,可能是一些空白?选中打印(df.columns.tolist())
def fun(foo):
b = foo['start'] < foo['end']
foo[['start','end']] = np.where(np.column_stack([b,b]),
foo[['start','end']],
foo[['end','start']])
return foo
print (fun(foo))
CHR start end Strand Peak Ratio Annotation
0 chr1 1 2 + 0.10 NA TSS1
1 chr2 3 4 - 0.03 NA TSS2
2 chr3 6 7 + 0.70 NA TSS3