python开发_csv(Comma Separated Values)_逗号分隔值_常用导入导出格式_完整版_博主推荐
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'''
在python中，CSV(Comma Separated Values)，从字面上面理解为：逗号分隔值
举个例子，如：test_csv = 'one, two, three, 4, 5'
对于test_csv这个变量来说，他里面就存放着这样的值：逗号分隔的值。这样的形式
在导入和导出中非常常见，如python(version:3.3.2)的API中所描述的一样：
The so-called CSV(Comma Separated Values) format is the most
common import and export for spreadsheets and databases.
csv模块定义了以下函数：
csv.reader(csvfile, dialect = 'excel', **fmtparams)
Retuen a reader object which will iterate over lines
in the given csvfile.
A short usage example:
import csv
with open('eggs.csv', newline = '') as cf:
spamreader = csv.reader(cf, delimiter = ' ',quotechar = '|')
for row in spamreader:
print(','.join(row))
csv.write(csvfile, dialect = 'excel', **fmtparams)
Return a writer object reaponsible for converting the
user's data into delimited strings on the given file-like
object.
A short usage example:
import csv
with open('eggs.csv', 'w', newline = '') as cf:
spamwrite = csv.writer(cf, delimiter = ' ', quotechar = '|', quoting = csv.QUOTE_MINIMAL)
spamwriter.writerow(['Spam'] * 5 + ['Baked Beans'])
spamwriter.writerow(['Spam', 'Lovely Spam', 'Wonderful Spam'])
'''
一下是我做的demo:
运行效果：
Python 3.3.2 (v3.3.2:d047928ae3f6, May 16 2013, 00:03:43) on win32
Type "copyright", "credits" or "license()" for more information.
>>> ================================ RESTART ================================
>>>
The path dosen't exist!
Created the path
打开文件:
写入数据:['one', 'two', 'three', 'four']
打开文件:
读取行:['one,two,three,four']
one,two,three,four
##################################################
打开文件:
写入数据:['one', 'two', 'three', 'four']
写入数据:['1', '2', '3']
写入数据:['a', 'b', 'c', 'd']
写入数据:['中国', '美国', '日本', '韩国', '新加坡']
打开文件:
读取行:['one,two,three,four']
读取行:['1,2,3']
读取行:['a,b,c,d']
读取行:['中国,美国,日本,韩国,新加坡']
one,two,three,four
1,2,3
a,b,c,d
中国,美国,日本,韩国,新加坡
>>>
在C:\\test目录下面的情况：
====================================================
代码部分：
====================================================
1 #python csv
2
3 #Author : Hongten
4 #MailTo : hongtenzone@foxmail.com
5 #QQ : 648719819
6 #Blog : http://www.iyunv.com/hongten
7 #Create : 2013-08-21
8 #Version: 1.0
9
10 import os
11 import csv
12
13 '''
14 在python中，CSV(Comma Separated Values)，从字面上面理解为：逗号分隔值
15 举个例子，如：test_csv = 'one, two, three, 4, 5'
16 对于test_csv这个变量来说，他里面就存放着这样的值：逗号分隔的值。这样的形式
17 在导入和导出中非常常见，如python(version:3.3.2)的API中所描述的一样：
18
19 The so-called CSV(Comma Separated Values) format is the most
20 common import and export for spreadsheets and databases.
21
22 csv模块定义了以下函数：
23
24 csv.reader(csvfile, dialect = 'excel', **fmtparams)
25 Retuen a reader object which will iterate over lines
26 in the given csvfile.
27 A short usage example:
28 import csv
29 with open('eggs.csv', newline = '') as cf:
30 spamreader = csv.reader(cf, delimiter = ' ',quotechar = '|')
31 for row in spamreader:
32 print(','.join(row))
33
34 csv.write(csvfile, dialect = 'excel', **fmtparams)
35 Return a writer object reaponsible for converting the
36 user's data into delimited strings on the given file-like
37 object.
38
39 A short usage example:
40 import csv
41 with open('eggs.csv', 'w', newline = '') as cf:
42 spamwrite = csv.writer(cf, delimiter = ' ', quotechar = '|', quoting = csv.QUOTE_MINIMAL)
43 spamwriter.writerow(['Spam'] * 5 + ['Baked Beans'])
44 spamwriter.writerow(['Spam', 'Lovely Spam', 'Wonderful Spam'])
45 '''
46
47 #global var
48 SHOW_LOG = True
49 #csv file apth
50 CSV_FILE_PATH = ''
51
52 def write_data_2_csv_file(path, data):
53 '''把数据写入到csv文件
54 这里对要写入的数据进行限制，
55 数据格式为一个列表：['one', 'two', 'three', 'four']
56 '''
57 if SHOW_LOG:
58 print('打开文件:[{}]'.format(path))
59 with open(path, 'w', newline = '') as cf:
60 writer = csv.writer(cf, delimiter = ',', quotechar = '|', quoting = csv.QUOTE_MINIMAL)
61 if SHOW_LOG:
62 print('写入数据:{}'.format(data))
63 writer.writerow(data)
64
65 def write_datas_2_csv_file(path, datas):
66 '''把数据写入到csv文件
67 这里对要写入的数据进行限制，
68 数据格式为一个列表,列表里面的每一个元素都是一个列表：
69 [
70 ['one', 'two', 'three', 'four'],
71 ['1', '2', '3'],
72 ['a', 'b', 'c', 'd']
73 ]
74 '''
75 if SHOW_LOG:
76 print('打开文件:[{}]'.format(path))
77 with open(path, 'w', newline = '') as cf:
78 writer = csv.writer(cf, delimiter = ',', quotechar = '|', quoting = csv.QUOTE_MINIMAL)
79 for row in datas:
80 if SHOW_LOG:
81 print('写入数据:{}'.format(row))
82 writer.writerow(row)
83
84 def read_csv_file(path):
85 '''读取指定的csv文件，并且把csv文件的内容以字符串的形式返回'''
86 if os.path.exists(path):
87 if SHOW_LOG:
88 print('打开文件:[{}]'.format(path))
89 content = ''
90 with open(path, newline = '') as cf:
91 reader = csv.reader(cf, delimiter = ' ', quotechar = '|')
92 try:
93 for row in reader:
94 if SHOW_LOG:
95 print('读取行:{}'.format(row))
96 c = ','.join(row) +'\n'
97 content += c
98 return content
99 except csv.Errow as e:
100 sys.exit('file {}, line {} : {}'.format(path, reader.line_num, e))
101 else:
102 print('不存在文件:[{}]'.format(path))
103
104 def mkdirs(path):
105 '''创建多级目录'''
106 if os.path.exists(path):
107 if SHOW_LOG:
108 print('The path [{}] existing!'.format(path))
109 else:
110 if SHOW_LOG:
111 print('The path [{}] dosen\'t exist!'.format(path))
112 os.makedirs(path)
113 if SHOW_LOG:
114 print('Created the path [{}]'.format(path))
115
116 def get_path(absPath):
117 '''获取到一个绝对路径的目录，
118 如绝对路径：'C:\\test\\test.csv'
119 则返回的是'C:\\test'
120 '''
121 if os.path.exists(absPath):
122 if SHOW_LOG:
123 print('the path [{}] existing!'.format(absPath))
124 return os.path.split(absPath)
125 else:
126 return os.path.split(absPath)
127
128 def init():
129 global SHOW_LOG
130 SHOW_LOG = True
131 global CSV_FILE_PATH
132 CSV_FILE_PATH = 'C:\\test\\test.csv'
133 csv_dir = get_path(CSV_FILE_PATH)
134 mkdirs(csv_dir)
135
136 def main():
137 init()
138 data = ['one', 'two', 'three', 'four']
139 datas = [
140 ['one', 'two', 'three', 'four'],
141 ['1', '2', '3'],
142 ['a', 'b', 'c', 'd'],
143 ['中国', '美国', '日本', '韩国', '新加坡']
144 ]
145 write_data_2_csv_file(CSV_FILE_PATH, data)
146 content = read_csv_file(CSV_FILE_PATH)
147 print(content)
148 print('#' * 50)
149 write_datas_2_csv_file(CSV_FILE_PATH,datas)
150 content = read_csv_file(CSV_FILE_PATH)
151 print(content)
152
153
154 if __name__ == '__main__':
155 main()
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