Python:使用 CSV 解析(？)变量，然后将其输出到另一个文件

Question

我是服务器管理员。我在没有编写太多脚本的情况下就过去了，但是唉——它已经抬起了丑陋的头。

总结:我有 example.csv，如下所示；

Stan,Marsh,Stan Marsh,1001,899,smarsh,smarsh@info.com
Eric,Cartman,Eric Cartman,1002,898,ecartman,ecartman@info.com

现在。我正在尝试读取 csv 文件。然后，我想从每一行中取出值并将其放入这样的东西中；

dn: cn=$CN,ou=People,dc=domain,dc=com
cn: $CN
gidnumber: 20
givenname $FN
homedirectory /home/users/$USER
loginshell: /bin/sh
objectclass: inetOrgPerson
objectclass: posixAccount
objectclass: top
sn: $LN
uid: $USERNAME
telephoneNumber: $TELE
uidnumber: $UIDN
userpassword: {CRYPT}mrpoo
mail: $EMAIL

如您所见，我正在尝试制作一个允许我导入用户名然后自动填充变量的 LDIF 文件。

我似乎无法将各个部分拼凑起来。

我也没有走多远。我学会了打印行，耶...!

import csv

with open('example.csv', 'rb') as f:
        reader = csv.reader(f)
        for row in reader:
                print row

我认为逻辑如下。

• 导入 .CSV。遍历行。
• 将数据放入变量。
• 将最终产品(打印件？)输出到“Output_File”
• 循环直到 EOF？

如有任何帮助，我们将不胜感激。

Answer 1

像这样的东西应该行得通。

CSV 模块对于像您这样的文件来说太过分了。

我在这里使用的一些 Python 习语:

• dict(zip(keys, values)) -- 压缩键列表和值列表； dict 函数(或 dict.update)可以将它们消化为键值对以添加到字典中
• 映射形式的字符串插值 (%(foo)s) 然后可以消化一个 dict

defaults 位在那里，因此字符串插值不会因缺失值而阻塞。适应您的需求。 :)

.

if True:  # For testing -- use the other branch to read from a file
    # Declare some test content in a string...
    input_content = """
Stan,Marsh,Stan Marsh,1001,899,smarsh,smarsh@info.com
Eric,Cartman,Eric Cartman,1002,898,ecartman,ecartman@info.com
    """.strip()
    # And use the StringIO module to create a file-like object from it.
    from StringIO import StringIO
    input_file = StringIO(input_content)
else:
    # Or just open the file as normal. In a short script like this,
    # one doesn't need to worry about closing the file - that will happen
    # when the script ends.
    input_file = open('example.csv', 'rb')


# Declare the fields in the order they are in the file.
# zip() will use this later with the actual fields from the file
# to create a dict mapping.
fields = ('FN', 'LN', 'NAME', 'UIDN', 'GIDN', 'CN', 'EMAIL')  # Fields, in order

# Declare a template for the LDIF file. The %(...)s bits will be
# later interpolated with the dict mapping created for each input row.
template = u"""
dn: cn=%(CN)s,ou=People,dc=domain,dc=com
cn: %(CN)s
gidnumber: 20
givenname %(FN)s
homedirectory /home/users/%(USER)s
loginshell: /bin/sh
objectclass: inetOrgPerson
objectclass: posixAccount
objectclass: top
sn: %(LN)s
uid: %(USERNAME)s
telephoneNumber: %(TELE)s
uidnumber: %(UIDN)s
userpassword: {CRYPT}mrpoo
mail: %(EMAIL)s
"""

for line in input_file:
    # Create `vals` with some default values. These would be overwritten
    # if the CSV data (and of course the declared fields) contain them.
    vals = {"USER": "XXX", "TELE": "XXX", "USERNAME": "XXX"}

    # line.strip().split() will turn the string line,
    # for example 'foo,baz,bar\n' (trailing new line `strip`ped out)
    # into the list ['foo', 'baz', 'bar'].
    # zipping it with, say, ['LN', 'FN', 'EMAIL'] would yield
    # [('LN', 'foo'), ('FN', 'baz'), ('EMAIL', 'bar')] -- 
    # ie. a list of tuples with a key and a value.
    # This can be used by the `dict.update` function to replace and augment
    # the default values declared above.

    vals.update(zip(fields, line.strip().split(",")))

    # Finally, use the interpolation operator % to merge the template with the
    # values for this line and print it to standard output.

    print template % vals