排序
df.sort_values(by=[‘ColName’], ascending=False)

转换类型
import pandas as pd
list = [‘count’]
for i in list:
data[i]=data[i].astype(‘float’)

dict_keys转变为列表list[]

python3.6版本以上

假设字典：

      dict =  {3: 9, 2: 9, 1: 8, 0: 4}

print(dict.keys())

输出为 dictkey= dict_keys([3, 2, 1, 0])

如果需要提取keys中的字段的话，需要list的转化

list(dict.keys())

输出为 [3, 2, 1, 0]

newlist = []
for i in newdict.keys():
newlist.append(i)

group :
data.groupby(‘year2’)[‘amt’].count()

取唯一去重值：
numbers = [1, 2, 2, 3, 3, 4, 5]

def get_unique_numbers(numbers):

list_of_unique_numbers = []

unique_numbers = set(numbers)

for number in unique_numbers:
    list_of_unique_numbers.append(number)

return list_of_unique_numbers

print(get_unique_numbers(numbers))

result: [1, 2, 3, 4, 5]

方法2：
for number in unique_numbers:
list_of_unique_numbers.append(number)
方法3：
unique_numbers = list(set(numbers))

for number in numbers:
if number in unique:
continue
else:
unique.append(number)

if number not in unique:
unique.append(number)