Strings

Concatenation

Use .join to to concatenate strings

✅ Good

names = ["Peter", "Albert", "Cleo", "Ember"]
output = ", ".join(names)

❌ Bad

names = ["Peter", "Albert", "Cleo", "Ember"]
output = ""
for name in names:
    output += name
    if not is_last_element(name):
        output += ", "

🎭 Compare

# Good
names = ["Peter", "Albert", "Cleo", "Ember"]
output = ", ".join(names)

# Bad
names = ["Peter", "Albert", "Cleo", "Ember"]
output = ""
for name in names:
    output += name
    if not is_last_element(name):
        output += ", "

💡 learnt from:

• Source: Raymond Hettinger

• Reference: Transform Python Slides

f-Strings

Use f-String for simple placeholder expressions

✅ Good

output = f"Firstname: {user.first_name}, Lastname: {user.last_name}, Age: {user.age}"

❌ Bad

output = "Firstname: {}, Lastname: {}, Age: {}".format(
    user.first_name, user.last_name, user.age
)

🎭 Compare

# Good
output = f"Firstname: {user.first_name}, Lastname: {user.last_name}, Age: {user.age}"

# Bad
output = "Firstname: {}, Lastname: {}, Age: {}".format(
    user.first_name, user.last_name, user.age
)

String.format

Use the string format function for complex expressions

✅ Good

template = """
{heading} - from: {date}
---------------------------------
{users}
"""
output = template.format(
    heading="User Overview",
    date=datetime.now().strftime("%Y-%m-%d"),
    users="\n".join(
        (
            f"Firstname: {user.first_name}, Lastname: {user.last_name}, Age: {user.age}"
            for user in users
        )
    ),
)

❌ Bad

heading = "User Overview"
date = datetime.now().strftime("%Y-%m-%d")
output = f"{heading} - from: {date}" + "\n"
output += "---------------------------------" + "\n"
for user in users:
    output += (
        f"Firstname: {user.first_name}, Lastname: {user.last_name}, Age: {user.age}\n"
    )

🎭 Compare

# Good
template = """
{heading} - from: {date}
---------------------------------
{users}
"""
output = template.format(
    heading="User Overview",
    date=datetime.now().strftime("%Y-%m-%d"),
    users="\n".join(
        (
            f"Firstname: {user.first_name}, Lastname: {user.last_name}, Age: {user.age}"
            for user in users
        )
    ),
)

# Bad
heading = "User Overview"
date = datetime.now().strftime("%Y-%m-%d")
output = f"{heading} - from: {date}" + "\n"
output += "---------------------------------" + "\n"
for user in users:
    output += (
        f"Firstname: {user.first_name}, Lastname: {user.last_name}, Age: {user.age}\n"
    )

💡 learnt from:

• Source: Robert Smallshire , Austin Bingham

• References: Rober Smallshire - Courses, Austin Bingham - Courses