假设我有以下简单的情况:
import pandas as pd
def multiply(row):
global results
results.append(row[0] * row[1])
def main():
results = []
df = pd.DataFrame([{'a': 1, 'b': 2}, {'a': 3, 'b': 4}, {'a': 5, 'b': 6}])
df.apply(multiply, axis=1)
print(results)
if __name__ == '__main__':
main()
这将导致以下回溯:
Traceback (most recent call last):
File "<ipython-input-2-58ca95c5b364>", line 1, in <module>
main()
File "<ipython-input-1-9bb1bda9e141>", line 11, in main
df.apply(multiply, axis=1)
File "C:\Users\bbritten\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\core\frame.py", line 4262, in apply
ignore_failures=ignore_failures)
File "C:\Users\bbritten\AppData\Local\Continuum\Anaconda3\lib\site-packages\pandas\core\frame.py", line 4358, in _apply_standard
results[i] = func(v)
File "<ipython-input-1-9bb1bda9e141>", line 5, in multiply
results.append(row[0] * row[1])
NameError: ("name 'results' is not defined", 'occurred at index 0')
我知道我可以转到results = []
该if
语句以使此示例正常工作,但是有没有办法保持我现在拥有的结构并使其正常工作?