如何替换字符串中出现的所有特定字符？

发布于 2024-09-16 11:15:16 字数 624 浏览 4 评论 0原文

我正在将 csv 读入 a：

import csv
import collections
import pdb
import math
import urllib

def do_work():
  a=get_file('c:/pythonwork/cds/cds.csv')
  a=remove_chars(a)
  print a[0:10]

def get_file(start_file): #opens original file, reads it to array
  with open(start_file,'rb') as f:
    data=list(csv.reader(f))
  return (data)

def remove_chars(a):
  badchars=['a','b','c','d']
  for row in a:
    for letter in badchars:
      row[8].replace(letter,'')
  return a

我想替换第 8 个中出现的所有 ['a','b','c','d']具有空字符串的行的元素。 remove_chars 函数不起作用。

有更好的方法吗？

原文

I am reading a csv into a:

import csv
import collections
import pdb
import math
import urllib

def do_work():
  a=get_file('c:/pythonwork/cds/cds.csv')
  a=remove_chars(a)
  print a[0:10]

def get_file(start_file): #opens original file, reads it to array
  with open(start_file,'rb') as f:
    data=list(csv.reader(f))
  return (data)

def remove_chars(a):
  badchars=['a','b','c','d']
  for row in a:
    for letter in badchars:
      row[8].replace(letter,'')
  return a

I would like to replace all occurrences of ['a','b','c','d'] in the 8th element of the line with empty string. the remove_chars function is not working.

Is there a better way to do this?

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

乖乖哒 2024-09-23 11:15:16

问题是您没有对 的结果执行任何操作替换。在Python中，字符串是不可变的，因此任何操作字符串的操作都会返回一个新字符串，而不是修改原始字符串。

line[8] = line[8].replace(letter, "")

The problem is that you are not doing anything with the result of replace. In Python strings are immutable so anything that manipulates a string returns a new string instead of modifying the original string.

line[8] = line[8].replace(letter, "")

回复收藏 0 原文

断舍离 2024-09-23 11:15:16

我会使用没有翻译表的翻译方法。它删除最新 Python 版本中第二个参数中的字母。

def remove_chars(line):
    line7=line[7].translate(None,'abcd')
    return line[:7]+[line7]+line[8:]

line= ['ad','da','sdf','asd',
        '3424','342sfas','asdfaf','sdfa',
        'afase']
print line[7]
line = remove_chars(line)
print line[7]

I would use the translate method without translation table. It deletes the letters in second argument in recent Python versions.

def remove_chars(line):
    line7=line[7].translate(None,'abcd')
    return line[:7]+[line7]+line[8:]

line= ['ad','da','sdf','asd',
        '3424','342sfas','asdfaf','sdfa',
        'afase']
print line[7]
line = remove_chars(line)
print line[7]

回复收藏 0 原文

缪败 2024-09-23 11:15:16

您确实应该有多个输入，例如一个用于名字、中间名、姓氏，另一个用于年龄。如果你想玩得开心，你可以尝试：

>>> input_given="join smith 25"
>>> chars="".join([i for i in input_given if not i.isdigit()])
>>> age=input_given.translate(None,chars)
>>> age
'25'
>>> name=input_given.replace(age,"").strip()
>>> name
'join smith'

如果输入中有多个数字，这当然会失败。快速检查是：

assert(age in input_given)

并且：

assert(len(name)<len(input_given))

You really should have multiple input, e.g. one for firstname, middle names, lastname and another one for age. If you want to have some fun though you could try:

>>> input_given="join smith 25"
>>> chars="".join([i for i in input_given if not i.isdigit()])
>>> age=input_given.translate(None,chars)
>>> age
'25'
>>> name=input_given.replace(age,"").strip()
>>> name
'join smith'

This would of course fail if there is multiple numbers in the input. a quick check would be: