Unable to replace characters in a list-CodePudding

def rmv_spc(lst,a):
        a = str(a)
        for i in lst:
            i = str(i)
            i.replace(a,"")
        return lst
    print(rmv_spc([343, 893, 1948, 3433333, 2346],3))

The output is the always the same list.

CodePudding user response：

This would work,

def rmv_spc(lst,a):  
  for i in range(len(lst)):
    lst[i] = str(lst[i]).replace(str(a),"")

  return lst 

print(rmv_spc([343, 893, 1948, 3433333, 2346],3))

Output -

['4', '89', '1948', '4', '246']

Your code was successfully replacing the characters from each item in the list, but it wasn't replacing the old item with the new one.

CodePudding user response：

Using i.replace(a, "") only returns the replaced string. You need to assign the result back into your list. To do this, you need to edit lst with an index i:

def rmv_spc(lst, a):
    a = str(a)
    for i in range(len(lst)):
        x = str(lst[i])
        lst[i] = x.replace(a, "")
    return lst

A better way would be to use a list comprehension:

def rmv_spc(lst, a):
    a = str(a)
    return [str(x).replace(a, "") for x in lst]

This is how replace works:

# Assign x
>>> x = 'abc'
>>> x
'abc'
# Replace 'a' with nothing
>>> x.replace('a','')
'bc'
# That is the result that we wanted, but x is still the same
>>> x
'abc'
# So we need to say that x = that result
>>> x = x.replace('a','')
>>> x
'bc'