How to Concatenate Nested Python Lists into a Formatted String

Problem Overview

A user asked how to convert a nested list like [["TDD", "(38套)"], ["2TR", "(23套)"], ["FDD", "(18套)"]] into a single string where each pair is concatenated and separated by line breaks, e.g. "TDD(38套)\n2TR(23套)\nFDD(18套)".

Solution 1 – Simple Loop

list1 = [["TDD", "(38套)"], ["2TR", "(23套)"], ["FDD", "(18套)"]]
string1 = ""
for item in list1:
    string1 += item[0] + item[1] + "
"
print(string1)

This loop iterates over each sub‑list, concatenates the two elements, appends a newline, and prints the result.

Solution 2 – Using a List and join

list1 = [["TDD", "(38套)"], ["2TR", "(23套)"], ["FDD", "(18套)"]]
text = []
for data in list1:
    data1 = data[0] + data[1]
    text.append(data1)
final_text = "
".join(str(i) for i in text)
print(final_text)

This approach builds a temporary list of the concatenated pairs and then joins them with newline characters, achieving the same output.

Solution 3 – One‑Liner with List Comprehension

list1 = [["TDD", "(38套)"], ["2TR", "(23套)"], ["FDD", "(18套)"]]
result = "
".join([a + b for a, b in list1])
print(result)

The list comprehension directly creates the formatted strings, and join combines them.

All three methods produce the expected formatted string and can be chosen based on readability preferences.