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Shahrouz Nikseresht
Shahrouz Nikseresht

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Python Strings Explained Simply (Common Operations and Methods)

#python #beginners #programming #tutorial

Strings are used to handle text in Python. They are one of the most common data types and come with many built-in tools.

What is a string?

A string is text enclosed in single quotes ' ' or double quotes " ".

name = "Alex"
message = 'Hello, Python!'
multiline = """This is a
multi-line string."""
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Strings are immutable, which means you cannot change them directly. Operations create new strings instead.

Basic operations

Concatenate (join) strings with +:

greeting = "Hello" + " " + "Alex"
print(greeting)  # Hello Alex
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Repeat a string with *:

stars = "*" * 10
print(stars)  # **********
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Get the length with len():

print(len(name))  # 4
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Accessing characters

Use indexes to get individual characters. Indexes start at 0.

text = "Python"

print(text[0])  # P
print(text[-1]) # n (last character)
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Slice to get a substring:

print(text[1:4])  # yth
print(text[:3])   # Pyt (from start)
print(text[3:])   # hon (to end)
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Common string methods

Convert case:

text = "hello python"

print(text.upper())   # HELLO PYTHON
print(text.lower())   # hello python
print(text.title())   # Hello Python
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Replace parts:

message = "I like cats"
new_message = message.replace("cats", "dogs")
print(new_message)  # I like dogs
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Split into a list:

words = "apple,banana,cherry"
word_list = words.split(",")
print(word_list)  # ['apple', 'banana', 'cherry']
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Check content:

email = "user@example.com"

print(email.startswith("user"))  # True
print(email.endswith(".com"))    # True
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Formatting strings

Use f-strings for clean formatting:

name = "Alex"
age = 25

print(f"{name} is {age} years old.")  # Alex is 25 years old.
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Common mistake: trying to change a string directly

Strings are immutable, so this causes an error:

text = "hello"
text[0] = "H"  # TypeError: 'str' object does not support item assignment
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Create a new string instead:

new_text = "H" + text[1:]
print(new_text)  # Hello
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Quick summary

  • Create strings with quotes.
  • Use indexing and slicing to access parts.
  • Apply methods like .upper(), .lower(), .replace(), and .split().
  • Use f-strings for easy formatting.
  • Remember strings are immutable.

Practice common operations on strings. They are essential for handling text in Python programs.

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