將函數(shù)應(yīng)用于數(shù)據(jù)框我目前有以下數(shù)據(jù)框：數(shù)據(jù)url visitorshttp://somedomain.com 200000http://someotherdomain.com 150000http://somenewdomain.com 11000對(duì)于數(shù)據(jù)框中的每一行，我喜歡將兩個(gè)函數(shù)應(yīng)用于 url 列，然后將每個(gè)結(jié)果寫入兩個(gè)不同的列“meta”和“content”。職能：def metacrawler(url) ... return datadef contentcrawler(url) ... return data# Counterprogress = 0環(huán)形for index, row in data.iterrows(): print(str(progress)," out of ",str(len(data))) print('Starting meta crawling.') row['meta'] = metacrawler(row["url"]) print('Starting content crawling.') row['content'] = contentcrawler(row["url"]) print('Complete.') progress += 1但是，當(dāng)我在幾次迭代后中止該過程時(shí)，我發(fā)現(xiàn)沒有數(shù)據(jù)寫入數(shù)據(jù)框中。也沒有創(chuàng)建列。我做錯(cuò)了什么？
1 回答
MMMHUHU
TA貢獻(xiàn)1834條經(jīng)驗(yàn) 獲得超8個(gè)贊
您可以使用該.apply()功能的文檔與result_type='expand'
In [3]: df = pd.DataFrame({'one':[1,2,3,4], 'two':[5,6,7,8]})
In [4]: df.apply(lambda x: (sum(x), sum(x)), axis=1, result_type='expand')
Out[4]:
0 1
0 6 6
1 8 8
2 10 10
3 12 12
In [5]: df[['new', 'etc']] = df.apply(lambda x: (sum(x), sum(x)), axis=1, result_type='expand')
In [6]: df
Out[6]:
one two new etc
0 1 5 6 6
1 2 6 8 8
2 3 7 10 10
3 4 8 12 12
編輯：如果要顯示進(jìn)度，請(qǐng)單獨(dú)定義應(yīng)用功能即
def func(row):
print(row)
return sum(row), sum(row)
In [3]: df = pd.DataFrame({'one':[1,2,3,4], 'two':[5,6,7,8]})
In [4]: df.apply(func), axis=1, result_type='expand')
Out[4]:
0 1
0 6 6
1 8 8
2 10 10
3 12 12
In [5]: df[['new', 'etc']] = df.apply(lambda x: (sum(x), sum(x)), axis=1, result_type='expand')
In [6]: df
Out[6]:
one two new etc
0 1 5 6 6
1 2 6 8 8
2 3 7 10 10
3 4 8 12 12
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