Python Pandas每12行重复一次相同的数字

Question

我想创建"Year"列，从2000年到2018年，每12行重复一次每年的值，如下所示：

1   2000
2   2000
3   2000
4   2000
5   2000
6   2000
7   2000
8   2000
9   2000
10  2000
11  2000
12  2000
1   2001
2   2001
3   2001
4   2001
5   2001
6   2001
7   2001
8   2001
9   2001
10  2001
11  2001
12  2001

Answer 1

这应该做到：

df = pd.DataFrame({'Year': [year for year in range(2000, 2019)]})
df = df.loc[df.index.repeat(12)]

您也可以重置索引：

df = df.loc[df.index.repeat(12)].reset_index(drop=True)

Answer 2

这样？

for year in range(2000, 2019):
for month in range(1, 13):
print(month, "t", year)

输出：

1    2000
2    2000
3    2000
4    2000
5    2000
...
...
...
7    2018
8    2018
9    2018
10   2018
11   2018
12   2018

Answer 3

你的意思是这样的吗：

Year = []
for i in range(12*19):
Year.append(2000+int(i/12))
print(Year)

返回[2000, 2000, 2000, 2000, 2000, 2000, 2000, 2000, 2000, 2000, 2000, 2000, 2001, 2001, 2001, 2001, 2001, 2001, 2001, 2001, 2001, 2001, 2001, 2001, 2002, 2002, 2002, 2002, 2002, 2002, 2002, 2002, 2002, 2002, 2002, 2002, 2003, 2003, 2003, 2003, 2003, 2003, 2003, 2003, 2003, 2003, 2003, 2003, 2004, 2004, 2004, 2004, 2004, 2004, 2004, 2004, 2004, 2004, 2004, 2004, 2005, 2005, 2005, 2005, 2005, 2005, 2005, 2005, 2005, 2005, 2005, 2005, 2006, 2006, 2006, 2006, 2006, 2006, 2006, 2006, 2006, 2006, 2006, 2006, 2007, 2007, 2007, 2007, 2007, 2007, 2007, 2007, 2007, 2007, 2007, 2007, 2008, 2008, 2008, 2008, 2008, 2008, 2008, 2008, 2008, 2008, 2008, 2008, 2009, 2009, 2009, 2009, 2009, 2009, 2009, 2009, 2009, 2009, 2009, 2009, 2010, 2010, 2010, 2010, 2010, 2010, 2010, 2010, 2010, 2010, 2010, 2010, 2011, 2011, 2011, 2011, 2011, 2011, 2011, 2011, 2011, 2011, 2011, 2011, 2012, 2012, 2012, 2012, 2012, 2012, 2012, 2012, 2012, 2012, 2012, 2012, 2013, 2013, 2013, 2013, 2013, 2013, 2013, 2013, 2013, 2013, 2013, 2013, 2014, 2014, 2014, 2014, 2014, 2014, 2014, 2014, 2014, 2014, 2014, 2014, 2015, 2015, 2015, 2015, 2015, 2015, 2015, 2015, 2015, 2015, 2015, 2015, 2016, 2016, 2016, 2016, 2016, 2016, 2016, 2016, 2016, 2016, 2016, 2016, 2017, 2017, 2017, 2017, 2017, 2017, 2017, 2017, 2017, 2017, 2017, 2017, 2018, 2018, 2018, 2018, 2018, 2018, 2018, 2018, 2018, 2018, 2018, 2018]