In [3]: df=pd.DataFrame(np.random.randn(5,5)) In [4]: df.columns=list('ABCDE') In [21]: df.iloc[1,1]=np.nan In [30]: df Out[30]: A B C D E 0 NaN -0.785578 -0.688584 -0.335229 -1.981495 1 0.094032 NaN 1.482541 0.160781 0.106237 2 -1.912919 1.432783 NaN NaN 1.212469 3 -0.549426 0.236417 0.087149 NaN 1.089239 4 -0.056149 -0.696856 1.137570 0.855886 NaN #####isnull() == True で NaN を持つ行だけを抽出できる isnull(
![Pandasで NaN (Null) の行だけ抽出 - Qiita](https://cdn-ak-scissors.b.st-hatena.com/image/square/fe08530cbca5b2d38cc449383f6d6ef321520add/height=288;version=1;width=512/https%3A%2F%2Fqiita-user-contents.imgix.net%2Fhttps%253A%252F%252Fcdn.qiita.com%252Fassets%252Fpublic%252Farticle-ogp-background-412672c5f0600ab9a64263b751f1bc81.png%3Fixlib%3Drb-4.0.0%26w%3D1200%26mark64%3DaHR0cHM6Ly9xaWl0YS11c2VyLWNvbnRlbnRzLmltZ2l4Lm5ldC9-dGV4dD9peGxpYj1yYi00LjAuMCZ3PTk3MiZoPTM3OCZ0eHQ9UGFuZGFzJUUzJTgxJUE3JTIwTmFOJTIwJTI4TnVsbCUyOSUyMCVFMyU4MSVBRSVFOCVBMSU4QyVFMyU4MSVBMCVFMyU4MSU5MSVFNiU4QSVCRCVFNSU4NyVCQSZ0eHQtYWxpZ249bGVmdCUyQ3RvcCZ0eHQtY29sb3I9JTIzMjEyMTIxJnR4dC1mb250PUhpcmFnaW5vJTIwU2FucyUyMFc2JnR4dC1zaXplPTU2JnM9M2I3ZTQ0ZTUwNDI2NTk0NGQxMTlmYWU2ZDAzNzMwMzY%26mark-x%3D142%26mark-y%3D57%26blend64%3DaHR0cHM6Ly9xaWl0YS11c2VyLWNvbnRlbnRzLmltZ2l4Lm5ldC9-dGV4dD9peGxpYj1yYi00LjAuMCZoPTc2Jnc9NzcwJnR4dD0lNDByeW9rMzMmdHh0LWNvbG9yPSUyMzIxMjEyMSZ0eHQtZm9udD1IaXJhZ2lubyUyMFNhbnMlMjBXNiZ0eHQtc2l6ZT0zNiZ0eHQtYWxpZ249bGVmdCUyQ3RvcCZzPWZjNmE1NTZlNDUxYjIyNjNlMTk0NjY0OTY5ZDM0MTI1%26blend-x%3D142%26blend-y%3D486%26blend-mode%3Dnormal%26s%3De9580cb9e8c2691fcaef942b1506fe93)