﻿ Python: Remove unwanted characters from a given string - w3resource

# Python: Remove unwanted characters from a given string

## Python String: Exercise-89 with Solution

Write a Python program to remove unwanted characters from a given string.

Sample Solution:-

Python Code:

``````def remove_chars(str1, unwanted_chars):
for i in unwanted_chars:
str1 = str1.replace(i, '')
return str1

str1 = "Pyth*^on Exercis^es"
str2 = "A%^!B#*CD"

unwanted_chars = ["#", "*", "!", "^", "%"]
print ("Original String : " + str1)
print("After removing unwanted characters:")
print(remove_chars(str1, unwanted_chars))
print ("\nOriginal String : " + str2)
print("After removing unwanted characters:")
print(remove_chars(str2, unwanted_chars))
```
```

Sample Output:

```Original String : Pyth*^on Exercis^es
After removing unwanted characters:
Python Exercises

Original String : A%^!B#*CD
After removing unwanted characters:
ABCD
```

Flowchart:

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﻿

## Python: Tips of the Day

Check if a given key already exists in a dictionary:

In is the intended way to test for the existence of a key in a dict.

```d = {"key1": 10, "key2": 23}

if "key1" in d:
print("this will execute")

if "nonexistent key" in d:
print("this will not")
```

If you wanted a default, you can always use dict.get():

```d = dict()

for i in range(100):
key = i % 10
d[key] = d.get(key, 0) + 1
```

and if you wanted to always ensure a default value for any key you can either use dict.setdefault() repeatedly or defaultdict from the collections module, like so:

```from collections import defaultdict

d = defaultdict(int)

for i in range(100):
d[i % 10] += 1
```

but in general, the in keyword is the best way to do it.

Ref: https://bit.ly/2XPMRyz