Master Python String Manipulation: 11 Essential Techniques

This article presents a collection of common Python string manipulation techniques, each accompanied by concise code examples.

1. Convert string case

value = "wangdianchao"
# Convert to uppercase
big_value = value.upper()
print(big_value)
# Convert to lowercase
small_value = big_value.lower()
print(small_value)

2. Check if input can be converted to a number

num = input("Enter content:")
# Determine if the string represents a digit
flag = num.isdigit()
print(flag)

3. Remove spaces from a string

user = input("Please enter username:")
# Remove trailing spaces
new_user = user.rstrip()
print(new_user)
# Remove leading spaces
new_user = user.lstrip()
print(new_user)
# Remove spaces on both sides (or newlines)
new_user = user.strip()
print(new_user)

4. Replace characters in a string

message = input("Please enter information:")
# Replace "大爷" with "**"
data = message.replace('大爷', '**')
print(data)
# Replace only the first occurrence
data = message.replace('大爷', '**', 1)
print(data)
# Replace the first two occurrences
data = message.replace('大爷', '**', 2)
print(data)

5. Split a string

message = "当清晨的一缕阳光透过窗帘上的空隙映照在沉睡的脸庞时，微微张开的双眼朦胧地注视着周遭的一切，新的一天悄然而至。"
# Split by comma
data = message.split('，')
print(data)
# Split once
data = message.split('，', 1)
print(data)
# Split from the right once
data = message.rsplit('，', 1)
print(data)

6. Check if a string starts with a substring

str_val = "this is string example....wow!!!"
print(str_val.startswith('this'))
# Using start and end positions
print(str_val.startswith('is', 2, 4))
print(str_val.startswith('this', 2, 4))

7. Check if a string ends with a substring

str_val = "this is string example....wow!!!"
suffix = "wow!!!"
print(str_val.endswith(suffix))
print(str_val.endswith(suffix, 20))
suffix = "is"
print(str_val.endswith(suffix, 2, 4))
print(str_val.endswith(suffix, 2, 6))

8. Format a string

template = "Website: {name}, URL: {url}"
print(template.format(name="Baidu", url="www.baidu.com"))

9. Change string encoding

str_val = "this is string example....wow!!!"
print(str_val.encode('utf-8'))

10. Join elements of a sequence into a string

sep = "-"
seq = ("a", "b", "c")  # Elements must be strings
print(sep.join(seq))

11. Convert between string and binary

data = '王佃超'
# Convert string to binary
binary_data = data.encode('utf-8')
# Convert binary back to string
text = binary_data.decode('utf-8')
print(text)