[Python]pandas中Series和读取外部数据

[Python]pandas中Series和读取外部数据

Series的创建，索引和值

import pandas as pd
import string 

# 带标签的数组
t1 = pd.Series([1,2,31,12,3,4])

print(t1)

t2 = pd.Series([1,23,2,2,1],index = list("abcde"))

print(t2)

temp_dict = {"name":"xiaohong","age":30,"tel":10086}

t3 = pd.Series(temp_dict)

print(t3)


t4 = {string.ascii_uppercase[i]:i for i in range(10)}

print(t4)

t4 = pd.Series(t4)

print(t4)

t4 = pd.Series(t4,index = list(string.ascii_uppercase[5:15]))

print(t4)


t4 = t4.astype(float)

print(t4)


print(t4["H"])

print(t4[["G","H"]])



print(t1[t1 > 3])


print(t3.index)

for i in t3.index:
    print(i)
    
print(type(t3.index))

print(len(t3.index))


print(t3.values)


print(type(t3.values))

pandas之读取外部数据

pandas读取csv文件

import pandas as pd

# pandas读取csv中的文件
df = pd.read_csv("./dogNames2.csv")

print(df)

运行结果:

pandas读取mysql数据库

example 01

import pymysql
import pandas as pd

conn = pymysql.connect(	
    host = 'localhost',	
    user = 'root',	
    passwd = '8888.216',	
    db = 'yuoj',	
    port=3306,	
    charset = 'utf8'	
)	
df = pd.read_sql('select * from question_submit',conn)	


print(df)

运行结果:

example 02

import pymysql
import pandas as pd

conn = pymysql.connect(	
    host = 'localhost',	
    user = 'root',	
    passwd = '8888.216',	
    db = 'yuoj',	
    port=3306,	
    charset = 'utf8'	
)	
df = pd.read_sql('select * from question_submit',conn)

#
print(df.head())

# 显示头部5行
print(df.head(5))

# 显示末尾5行
print(df.tail(5))

# 显示df的概览
print(df.info())


print(df.describe())

运行结果: