我想导入2种CSV文件，有的使用“;” 为分隔符和其他人使用“”。 到目前为止，我一直在接下来的两行之间的切换：
reader=csv.reader(f,delimiter=';')
要么
reader=csv.reader(f,delimiter=',')
是否有可能不指定分隔符，让为正确的分隔符程序检查？
下面（搅拌机和沙尔斯）的解决方案，似乎也为逗号分隔的文件（Libroffice产生的），但不是分号分隔的文件（与MS Office生成的）工作。 下面是一个分号分隔的文件的第一行：
ReleveAnnee;ReleveMois;NoOrdre;TitreRMC;AdopCSRegleVote;AdopCSAbs;AdoptCSContre;NoCELEX;ProposAnnee;ProposChrono;ProposOrigine;NoUniqueAnnee;NoUniqueType;NoUniqueChrono;PropoSplittee;Suite2LecturePE;Council PATH;Notes
1999;1;1;1999/83/EC: Council Decision of 18 January 1999 authorising the Kingdom of Denmark to apply or to continue to apply reductions in, or exemptions from, excise duties on certain mineral oils used for specific purposes, in accordance with the procedure provided for in Article 8(4) of Directive 92/81/EEC;U;;;31999D0083;1998;577;COM;NULL;CS;NULL;;;;Propos* are missing on Celex document
1999;1;2;1999/81/EC: Council Decision of 18 January 1999 authorising the Kingdom of Spain to apply a measure derogating from Articles 2 and 28a(1) of the Sixth Directive (77/388/EEC) on the harmonisation of the laws of the Member States relating to turnover taxes;U;;;31999D0081;1998;184;COM;NULL;CS;NULL;;;;Propos* are missing on Celex document
该csv模块似乎使用推荐CSV嗅探这个问题。
他们给下面的例子中，我已经适应了你的情况。
with open('example.csv', 'rb') as csvfile: # python 3: 'r',newline=""
dialect = csv.Sniffer().sniff(csvfile.read(1024), delimiters=";,")
csvfile.seek(0)
reader = csv.reader(csvfile, dialect)
# ... process CSV file contents here ...
让我们来尝试一下。
[9:13am][wlynch@watermelon /tmp] cat example
#!/usr/bin/env python
import csv
def parse(filename):
with open(filename, 'rb') as csvfile:
dialect = csv.Sniffer().sniff(csvfile.read(), delimiters=';,')
csvfile.seek(0)
reader = csv.reader(csvfile, dialect)
for line in reader:
print line
def main():
print 'Comma Version:'
parse('comma_separated.csv')
print
print 'Semicolon Version:'
parse('semicolon_separated.csv')
print
print 'An example from the question (kingdom.csv)'
parse('kingdom.csv')
if __name__ == '__main__':
main()
而我们的样本输入
[9:13am][wlynch@watermelon /tmp] cat comma_separated.csv
test,box,foo
round,the,bend
[9:13am][wlynch@watermelon /tmp] cat semicolon_separated.csv
round;the;bend
who;are;you
[9:22am][wlynch@watermelon /tmp] cat kingdom.csv
ReleveAnnee;ReleveMois;NoOrdre;TitreRMC;AdopCSRegleVote;AdopCSAbs;AdoptCSContre;NoCELEX;ProposAnnee;ProposChrono;ProposOrigine;NoUniqueAnnee;NoUniqueType;NoUniqueChrono;PropoSplittee;Suite2LecturePE;Council PATH;Notes
1999;1;1;1999/83/EC: Council Decision of 18 January 1999 authorising the Kingdom of Denmark to apply or to continue to apply reductions in, or exemptions from, excise duties on certain mineral oils used for specific purposes, in accordance with the procedure provided for in Article 8(4) of Directive 92/81/EEC;U;;;31999D0083;1998;577;COM;NULL;CS;NULL;;;;Propos* are missing on Celex document
1999;1;2;1999/81/EC: Council Decision of 18 January 1999 authorising the Kingdom of Spain to apply a measure derogating from Articles 2 and 28a(1) of the Sixth Directive (77/388/EEC) on the harmonisation of the laws of the Member States relating to turnover taxes;U;;;31999D0081;1998;184;COM;NULL;CS;NULL;;;;Propos* are missing on Celex document
如果我们执行该示例程序：
[9:14am][wlynch@watermelon /tmp] ./example
Comma Version:
['test', 'box', 'foo']
['round', 'the', 'bend']
Semicolon Version:
['round', 'the', 'bend']
['who', 'are', 'you']
An example from the question (kingdom.csv)
['ReleveAnnee', 'ReleveMois', 'NoOrdre', 'TitreRMC', 'AdopCSRegleVote', 'AdopCSAbs', 'AdoptCSContre', 'NoCELEX', 'ProposAnnee', 'ProposChrono', 'ProposOrigine', 'NoUniqueAnnee', 'NoUniqueType', 'NoUniqueChrono', 'PropoSplittee', 'Suite2LecturePE', 'Council PATH', 'Notes']
['1999', '1', '1', '1999/83/EC: Council Decision of 18 January 1999 authorising the Kingdom of Denmark to apply or to continue to apply reductions in, or exemptions from, excise duties on certain mineral oils used for specific purposes, in accordance with the procedure provided for in Article 8(4) of Directive 92/81/EEC', 'U', '', '', '31999D0083', '1998', '577', 'COM', 'NULL', 'CS', 'NULL', '', '', '', 'Propos* are missing on Celex document']
['1999', '1', '2', '1999/81/EC: Council Decision of 18 January 1999 authorising the Kingdom of Spain to apply a measure derogating from Articles 2 and 28a(1) of the Sixth Directive (77/388/EEC) on the harmonisation of the laws of the Member States relating to turnover taxes', 'U', '', '', '31999D0081', '1998', '184', 'COM', 'NULL', 'CS', 'NULL', '', '', '', 'Propos* are missing on Celex document']
它也可能是值得关注我使用的Python版本。
[9:20am][wlynch@watermelon /tmp] python -V
Python 2.7.2
为了解决这个问题，我已经创建了一个函数，它读取文件（标题）的第一行，并检测定界符。
def detectDelimiter(csvFile):
with open(csvFile, 'r') as myCsvfile:
header=myCsvfile.readline()
if header.find(";")!=-1:
return ";"
if header.find(",")!=-1:
return ","
#default delimiter (MS Office export)
return ";"
鉴于一个项目，既涉及，（逗号）和| （竖线）分隔的CSV文件，这是公形成，我尝试以下（如在给定的https://docs.python.org/2/library/csv.html#csv.Sniffer ）：
dialect = csv.Sniffer().sniff(csvfile.read(1024), delimiters=',|')
然而，在一个| -delimited文件，返回了“无法确定分隔符”异常。 这似乎合理地推测，如果每行有相同数量的分隔符（不包括任何可能用引号括起来）的嗅启发式可能是最好的。 因此，而不是读取文件的前1024个字节，我想读书的全部前两行：
temp_lines = csvfile.readline() + '\n' + csvfile.readline()
dialect = csv.Sniffer().sniff(temp_lines, delimiters=',|')
到目前为止，这是对我工作良好。
如果你正在使用DictReader你可以这样做：
#!/usr/bin/env python
import csv
def parse(filename):
with open(filename, 'rb') as csvfile:
dialect = csv.Sniffer().sniff(csvfile.read(), delimiters=';,')
csvfile.seek(0)
reader = csv.DictReader(csvfile, dialect=dialect)
for line in reader:
print(line['ReleveAnnee'])
我用这个用Python 3.5和它的工作这种方式。
我不认为这有可能是这完全通用的解决方案（我可能会使用的原因之一,作为分隔符的是，我的一些数据字段的需要能够包括; ...）。 对于决定一个简单的规则可能是简单地读取第一行（或以上），算多少,和; 它包含的字符（可能忽略那些引号内，如果任何你创建.csv文件正确和一致引用条目），并猜测，更频繁的两个是正确的分隔符。
