[转载]Python csv文件 相关操作
2020-08-26 本文已影响0人
AeroZ
https://www.cnblogs.com/liangxiyang/p/11272155.html
import csv
with open('/f.CSV', 'r') as f:
reader = csv.reader(f)
print(type(reader))
'''获取每一行'''
# for row in reader:
# print(row)
'''获取每一行'''
# result = list(reader)
# print(result[0])
'''获取某一列'''
for i in reader:
print(i[0])
Python对CSV文件的处理
https://cloud.tencent.com/developer/article/1357970
Python处理CSV与List的转换
作者:新手村的0级玩家
链接:https://www.jianshu.com/p/61b45b6b36aa
1.读取CSV文件到List
def readCSV2List(filePath):
try:
file=open(filePath,'r',encoding="gbk")# 读取以utf-8
context = file.read() # 读取成str
list_result=context.split("\n")# 以回车符\n分割成单独的行
#每一行的各个元素是以【,】分割的,因此可以
length=len(list_result)
for i in range(length):
list_result[i]=list_result[i].split(",")
return list_result
except Exception :
print("文件读取转换失败,请检查文件路径及文件编码是否正确")
finally:
file.close();# 操作完成一定要关闭
2.将List写入到CSV文件中
def writeList2CSV(myList,filePath):
try:
file=open(filePath,'w')
for items in myList:
for item in items:
file.write(item)
file.write(",")
file.write("\n")
except Exception :
print("数据写入失败,请检查文件路径及文件编码是否正确")
finally:
file.close();# 操作完成一定要关闭
另一篇文章:使用python读取csv并转化成list of list的方法
https://blog.csdn.net/birdflyinhigh/article/details/79685019
利用python转置csv文件
https://blog.csdn.net/baidu_41217766/article/details/96271603
df = pd.read_csv(file)
df.values
data = df.as_matrix()
data = list(map(list,zip(*data)))
data = pd.DataFrame(data)
data.to_csv('dataset/'+file,header=0,index=0)
Python之str型转成int型
https://www.cnblogs.com/fallenmoon/p/7200947.html
def fn(x,y):
return x*10+y
def char2num(s):
return {'0':0, '1':1, '2':2, '3':3, '4':4, '5':5, '6':6, '7':7, '8':8, '9':9}[s] # 特别注意这里,后面还有个 [s]
print(type(reduce(fn, map(char2num, '1738785'))))
print(reduce(fn, map(char2num, '1738785')))
from functools import reduce
def str2int(s):
def fn(x,y):
return x*10+y
def char2num(s):
return {'0':0, '1':1, '2':2, '3':3, '4':4, '5':5, '6':6, '7':7, '8':8, '9':9}[s]
return reduce(fn,map(char2num,s))
print(str2int('365779'))
print(type(str2int('365779')))
'''str转int'''
from functools import reduce
def str2int(s):
return reduce(lambda x,y:x*10+y, map(lambda s:{'0':0, '1':1, '2':2, '3':3, '4':4, '5':5, '6':6, '7':7, '8':8, '9':9,}[s], s))
python 一行语句实现if else
https://blog.csdn.net/weixin_44255799/article/details/100945329
value_when_true if condition_is_ture else value_when_condition_is_false
python利用numpy模块读取csv文件
https://blog.csdn.net/u012413551/article/details/87890989
python 借助numpy保存数据为csv格式的实现方法
https://www.jb51.net/article/143139.htm
借助numpy可以把数组或者矩阵保存为csv文件,也可以吧csv文件整体读取为一个数组或矩阵。
1. csv ==> matrix
import numpy
my_matrix = numpy.loadtxt(open("D:\\test.csv","rb"), delimiter=",", skiprows=0)
2. matrix ==> csv
import numpy
numpy.savetxt("new.csv", my_matrix, delimiter=',')