Python数据分析(4)pandas库的使用:数据的读写

函数一览表:

#coding=gbk
#pandas数据读写
#1csv和文本文件的读取
import numpy as np
import pandas as pd
mydata=pd.read_csv('D:\data\mydata.csv')    #读取数据
print(mydata)
#     color    object   name  others
# 0     red      book   haha       1
# 1   white       pen    NaN       4
# 2  yellow  notebook   this      12
# 3    blue      desk  smith       5
# 4   black      door  jerry       7

mydata1=pd.read_table('D:\data\mydata.csv',sep=',') #csv也是文本格式,但是需要指定  分隔符,
print(mydata1)
#     color    object   name  others
# 0     red      book   haha       1
# 1   white       pen    NaN       4
# 2  yellow  notebook   this      12
# 3    blue      desk  smith       5
# 4   black      door  jerry       7

#自定义表头
mydata2=pd.read_csv('D:\data\mydata1.csv')
print(mydata2)
#       red      book   haha   1
# 0   white       pen    NaN   4
# 1  yellow  notebook   this  12
# 2    blue      desk  smith   5
# 3   black      door  jerry   7
mydata3=pd.read_csv('D:\data\mydata1.csv',names=['color','object','name','others'])
print(mydata3)      
#     color    object   name  others    #添加了表头
# 0     red      book   haha       1
# 1   white       pen    NaN       4
# 2  yellow  notebook   this      12
# 3    blue      desk  smith       5
# 4   black      door  jerry       7

#读取文本文件
data1=pd.read_table('D:\data\data1.txt',sep='\s*')  #正则表达式为分隔符  空格\s
print(data1)
#    blue  black  white
# 0     1      2      3
# 1     4      5      6
# 2     7      8      9
#skiprows用法
data2=pd.read_table('D:\data\data2.txt')
print(data2)
#             hahhahah -----
# 0        -----------aha---
# 1          fenge----------
# 2  blue,black,white,yellow
# 3           hahhahah -----
# 4                  1,2,3,4
# 5                  5,6,7,8
# 6               1,22,33,44
# 7                 6,8,9,10
data3=pd.read_table('D:\data\data2.txt',sep=',',skiprows=[0,1,2,4]) #删除对应的行
print(data3)
#    blue  black  white  yellow
# 0     1      2      3       4
# 1     5      6      7       8
# 2     1     22     33      44
# 3     6      8      9      10
#读取梯txt文件部分数据
data4=pd.read_table('D:\data\data1.txt',sep='\s*',skiprows=[1],nrows=2) #skiprows定义起始行
print(data4)
#    blue  black  white
# 0     4      5      6
# 1     7      8      9

#在csv文件中写入数据
mydata2=pd.read_csv('D:\data\mydata1.csv')
print(mydata2)
#       red      book   haha   1
# 0   white       pen    NaN   4
# 1  yellow  notebook   this  12
# 2    blue      desk  smith   5
# 3   black      door  jerry   7
m=mydata2.to_csv('D:\data\data2.csv')
print(m)
#对于读取excel的xls同理,使用pd.read_excel();pd.to_excel()


#使用pandas对象实现序列化
frame=pd.DataFrame(np.arange(16).reshape(4,4),index=['up','down','left','right'])
print(frame)
frame.to_pickle('D:\data\datapickle.pkl') #保存到对应的文件路径当中
frame1=pd.read_pickle('D:\data\datapickle.pkl') #读取pkl格式的数据
print(frame1)
#         0   1   2   3
# up      0   1   2   3
# down    4   5   6   7
# left    8   9  10  11
# right  12  13  14  15

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转载自blog.csdn.net/qq_40587575/article/details/80633142