Python 3.x读写csv文件中数字的方法示例

## 读写csv文件
csv_file = 'datas.csv'
csv = open(csv_file,'w')
for i in range(1,20):
 csv.write(str(i) + ',')
 if i % 10 == 0:
  csv.write('\n')
csv.close()
result = []
with open(csv_file,'r') as f:
 for line in f:
  linelist = line.split(',')
  linelist.pop()# delete: \n
  for index, item in enumerate(linelist):
   result.append(int(item))
print('\nResult is \n' , result)

Result is
 [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19]

import os
json_dir = "../dir_json/2017-04/"
if not os.path.exists(json_dir):
 print("json dir not found")
 os.makedirs(json_dir)
 print("Create dir " + json_dir)

import json
json_file = open(json_dir + id + '.json', 'w', encoding='utf8')
json_file.write(json.dumps(data_dict, ensure_ascii=False))

>>> data = [1,2,3]
>>> for i, item in enumerate(data):
 print(i,item)
0 1
1 2
2 3

>>> line = 'one'
>>> for i, item in enumerate(line,4):
 print(i,item)
4 o
5 n
6 e

>>> print(int('-100'),int('0'),int('3'))
-100 0 3
>>> int(7788)
7788
>>> int(7.98)
7
>>> int('2.33')
Traceback (most recent call last):
 File "<pyshell#27>", line 1, in <module>
 int('2.33')
ValueError: invalid literal for int() with base 10: '2.33'