python常用命令有哪些

import pandas as pd

df=pd.read_csv(r’data/data.csv’)

data=df.sort_index(axis=0,ascending=False)

data=df.sort([‘date’],ascending=True升序，False降序)

data=data.reset_index(drop=True)

import matplotlib.pyplot as plt

x=data[‘date’]#日期是字符串形式

y=data[‘close price’]

plt.plot_date(x,y)

import numpy as np

np.std

import math

math.floor

from scipy import fftpack

hx= fftpack.hilbert(price)

data.order()

data.diff(1)#一阶差分

dataframe 删除元素

data.drop(元素位置)

import itertools

a = [[1,2,3],[4,5,6], [7], [8,9]]

out = list(itertools.chain.from_iterable(a))

data.columns=[‘num’,’price’]

import numpy as np

data= data.drop(data.loc[np.isnan(data.name.values)].index)

t=data.time.tolist()

date_time = datetime.datetime.strptime(str(t),’%Y-%m-%d %H:%M:%S’)

date_time=datetime.date(date_time.year,date_time.month,date_time.day)

past= date_time - datetime.timedelta(days=n*365)

np.sign

label={‘11’:’TP’,’1-1’:’FN’,’-11’:’FP’,’-1-1’:’TN’}

for i in range(len(data1)):

state=str(int(data1[i]))+str(int(data2[i]))

result.append(label[state])

from matplotlib.font_manager import FontProperties

font_set = FontProperties(fname=r”c:\windows\fonts\simsun.ttc”, size=15)

plt.title(u’中文’, fontproperties=font_set）

from time import time

time1=time()

time2=time()

print(time2-time1)