課題 · データ処理 上級 Python ·

Parse CSV

def parse_csv(text: str) -> list[list[str]]:

parse_csv('a,b,c\n1,2,3\n')  # -> [['a', 'b', 'c'], ['1', '2', '3']]
parse_csv('name,quote\r\n"Smith, J.","He said ""hi"""')  # -> [['name', 'quote'], ['Smith, J.', 'He said "hi"']]

• #1SpaceXAI Grok Build 0.1正解 · 17 / 17 件のテストにパス回答時間 42 秒 · 実行時間 481 ms · $0.01

  ✓	parse_csv('a,b,c\n1,2,3\n')期待値 [['a', 'b', 'c'], ['1', '2', '3']]	<1 ms
  ✓	parse_csv('name,quote\r\n"Smith, J.","He said ""hi"""')期待値 [['name', 'quote'], ['Smith, J.', 'He said "hi"']]	<1 ms

  ✓ <1 ms✓ <1 ms✓ <1 ms✓ <1 ms✓ <1 ms✓ <1 ms✓ 5 ms✓ <1 ms✓ <1 ms✓ 1 ms✓ <1 ms✓ <1 ms✓ <1 ms✓ <1 ms⏱ 467 ms
  コード

  def parse_csv(text: str) -> list[list[str]]:
      rows: list[list[str]] = []
      i = 0
      n = len(text)
      while i < n:
          row: list[str] = []
          while True:
              field: list[str] = []
              quoted = False
              if i < n and text[i] == '"':
                  quoted = True
                  i += 1
              while i < n:
                  c = text[i]
                  if quoted:
                      if c == '"':
                          if i + 1 < n and text[i + 1] == '"':
                              field.append('"')
                              i += 2
                              continue
                          else:
                              i += 1
                              quoted = False
                              break
                      else:
                          field.append(c)
                          i += 1
                  else:
                      if c == ',' or c == '\n' or c == '\r':
                          break
                      field.append(c)
                      i += 1
              row.append(''.join(field))
              if i >= n:
                  break
              c = text[i]
              if c == ',':
                  i += 1
                  continue
              elif c == '\n':
                  i += 1
                  break
              elif c == '\r':
                  i += 1
                  if i < n and text[i] == '\n':
                      i += 1
                  break
              else:
                  break
          rows.append(row)
      return rows

• #1MiniMax M3.1 Flash正解 · 17 / 17 件のテストにパス回答時間 14 秒 · 実行時間 493 ms · $0.0011

  ✓	parse_csv('a,b,c\n1,2,3\n')期待値 [['a', 'b', 'c'], ['1', '2', '3']]	1 ms
  ✓	parse_csv('name,quote\r\n"Smith, J.","He said ""hi"""')期待値 [['name', 'quote'], ['Smith, J.', 'He said "hi"']]	1 ms

  ✓ <1 ms✓ <1 ms✓ 2 ms✓ <1 ms✓ 2 ms✓ <1 ms✓ <1 ms✓ <1 ms✓ 1 ms✓ 2 ms✓ 1 ms✓ 1 ms✓ 1 ms✓ <1 ms⏱ 474 ms
  コード

  def parse_csv(text: str) -> list[list[str]]:
      rows: list[list[str]] = []
      row: list[str] = []
      field: list[str] = []
      in_quotes = False
      at_field_start = True
      ended_with_break = False
      i = 0
      n = len(text)
  
      while i < n:
          c = text[i]
  
          if in_quotes:
              if c == '"':
                  if i + 1 < n and text[i + 1] == '"':
                      field.append('"')
                      i += 2
                  else:
                      in_quotes = False
                      i += 1
              else:
                  field.append(c)
                  i += 1
              continue
  
          if at_field_start and c == '"':
              in_quotes = True
              at_field_start = False
              ended_with_break = False
              i += 1
          elif c == ',':
              row.append(''.join(field))
              field.clear()
              at_field_start = True
              ended_with_break = False
              i += 1
          elif c == '\n':
              row.append(''.join(field))
              field.clear()
              rows.append(row)
              row = []
              at_field_start = True
              ended_with_break = True
              i += 1
          elif c == '\r' and i + 1 < n and text[i + 1] == '\n':
              row.append(''.join(field))
              field.clear()
              rows.append(row)
              row = []
              at_field_start = True
              ended_with_break = True
              i += 2
          else:
              field.append(c)
              at_field_start = False
              ended_with_break = False
              i += 1
  
      if n and not ended_with_break:
          row.append(''.join(field))
          rows.append(row)
  
      return rows

• #1Anthropic Claude Haiku 5.5正解 · 17 / 17 件のテストにパス回答時間 2.3 秒 · 実行時間 524 ms · $0.0003

  ✓	parse_csv('a,b,c\n1,2,3\n')期待値 [['a', 'b', 'c'], ['1', '2', '3']]	<1 ms
  ✓	parse_csv('name,quote\r\n"Smith, J.","He said ""hi"""')期待値 [['name', 'quote'], ['Smith, J.', 'He said "hi"']]	2 ms

  ✓ <1 ms✓ <1 ms✓ <1 ms✓ <1 ms✓ <1 ms✓ <1 ms✓ <1 ms✓ <1 ms✓ <1 ms✓ <1 ms✓ <1 ms✓ <1 ms✓ <1 ms✓ <1 ms⏱ 514 ms
  コード

  def parse_csv(text: str) -> list[list[str]]:
      rows = []
      n = len(text)
      if n == 0:
          return rows
      row = []
      field = []
      i = 0
      in_quotes = False
      # track whether we are at start of a field (for quoted field detection)
      field_start = True
      while i < n:
          c = text[i]
          if in_quotes:
              if c == '"':
                  if i + 1 < n and text[i + 1] == '"':
                      field.append('"')
                      i += 2
                      continue
                  in_quotes = False
                  i += 1
                  continue
              field.append(c)
              i += 1
              continue
          if c == '"' and field_start:
              in_quotes = True
              field_start = False
              i += 1
              continue
          if c == ',':
              row.append(''.join(field))
              field = []
              field_start = True
              i += 1
              continue
          if c == '\r' and i + 1 < n and text[i + 1] == '\n':
              row.append(''.join(field))
              rows.append(row)
              row = []
              field = []
              field_start = True
              i += 2
              continue
          if c == '\n':
              row.append(''.join(field))
              rows.append(row)
              row = []
              field = []
              field_start = True
              i += 1
              continue
          field.append(c)
          field_start = False
          i += 1
      # end of text: finish last row if any content pending
      if field or row or not (text.endswith('\n')):
          row.append(''.join(field))
          rows.append(row)
      return rows

• #4Qwen3 Coder Next不正解 · 14 / 17 件のテストにパス回答時間 10.0 秒 · 実行時間 473 ms · $0.0005

  ✓	parse_csv('a,b,c\n1,2,3\n')期待値 [['a', 'b', 'c'], ['1', '2', '3']]	<1 ms
  ✓	parse_csv('name,quote\r\n"Smith, J.","He said ""hi"""')期待値 [['name', 'quote'], ['Smith, J.', 'He said "hi"']]	1 ms

  ✓ 3 ms✓ <1 ms✓ <1 ms✓ <1 ms✓ <1 ms✓ <1 ms✓ <1 ms✗ 不正解✗ 不正解✓ 2 ms✓ <1 ms✓ <1 ms✗ 不正解✓ <1 ms⏱ 458 ms
  コード

  def parse_csv(text: str) -> list[list[str]]:
      if not text:
          return []
      
      rows = []
      current_row = []
      current_field = []
      in_quotes = False
      i = 0
      n = len(text)
      
      while i < n:
          char = text[i]
          
          if in_quotes:
              if char == '"':
                  # Check if next character is also a quote
                  if i + 1 < n and text[i + 1] == '"':
                      current_field.append('"')
                      i += 2
                      continue
                  else:
                      in_quotes = False
                      i += 1
                      continue
              else:
                  current_field.append(char)
                  i += 1
                  continue
          else:
              # Not in quotes
              if char == '"':
                  in_quotes = True
                  i += 1
                  continue
              elif char == ',':
                  current_row.append(''.join(current_field))
                  current_field = []
                  i += 1
                  continue
              elif char == '\r':
                  # Handle \r\n or standalone \r
                  if i + 1 < n and text[i + 1] == '\n':
                      i += 1  # Skip \n
                  current_row.append(''.join(current_field))
                  current_field = []
                  rows.append(current_row)
                  current_row = []
                  i += 1
                  continue
              elif char == '\n':
                  current_row.append(''.join(current_field))
                  current_field = []
                  rows.append(current_row)
                  current_row = []
                  i += 1
                  continue
              else:
                  current_field.append(char)
                  i += 1
                  continue
      
      # Add the last field if exists
      if current_field or current_row:
          current_row.append(''.join(current_field))
          rows.append(current_row)
      
      # Handle trailing newline - if last row is empty after trailing newline, remove it
      # A line break at the very end does not start another row
      # So if the last row is just an empty field due to trailing newline, remove it
      if rows and len(rows[-1]) == 1 and rows[-1][0] == '' and text.endswith(('\r', '\n')):
          # Only remove if the text ended with a newline and the last row is empty
          # But we need to check if there was a field before the final newline
          # Reconstruct: the empty row should only be added if the line break was not at the very end
          # Actually, our logic already handled this: a trailing \n or \r\n adds an empty field and a new row
          # So we need to check if the last row is empty and the text ended with a newline
          # In that case, we should remove the last row
          rows.pop()
      
      return rows

  2回目の試行

  不正解 · 6 / 17 件のテストにパス回答時間 24 秒 · $0.0012

  モデルには失敗したテスト数、期待値と実際の返り値を含む失敗例、および隠蔽テストの入力値そのものではなく失敗理由のみが提示されました。順位やレーティングには影響しません。

  ✓	parse_csv('a,b,c\n1,2,3\n')期待値 [['a', 'b', 'c'], ['1', '2', '3']]	<1 ms
  ✗	parse_csv('name,quote\r\n"Smith, J.","He said ""hi"""')期待値 [['name', 'quote'], ['Smith, J.', 'He said "hi"']]出力値 [['name', 'quote']]	<1 ms

  ✓ <1 ms✗ 不正解✗ 不正解✗ 不正解✗ 不正解✗ 不正解✓ <1 ms✓ <1 ms✗ 不正解✗ 不正解✗ 不正解✗ 不正解✓ <1 ms✗ 不正解⏱ 732 ms

  コード

  def parse_csv(text: str) -> list[list[str]]:
      if not text:
          return []
      
      rows = []
      current_row = []
      current_field = []
      in_quotes = False
      i = 0
      n = len(text)
      
      while i < n:
          char = text[i]
          
          if in_quotes:
              if char == '"':
                  # Check if next character is also a quote
                  if i + 1 < n and text[i + 1] == '"':
                      current_field.append('"')
                      i += 2
                      continue
                  else:
                      in_quotes = False
                      i += 1
                      continue
              else:
                  current_field.append(char)
                  i += 1
                  continue
          else:
              # Not in quotes
              if char == '"':
                  in_quotes = True
                  i += 1
                  continue
              elif char == ',':
                  current_row.append(''.join(current_field))
                  current_field = []
                  i += 1
                  continue
              elif char == '\r':
                  # Handle \r\n or standalone \r
                  current_row.append(''.join(current_field))
                  current_field = []
                  rows.append(current_row)
                  current_row = []
                  if i + 1 < n and text[i + 1] == '\n':
                      i += 2
                  else:
                      i += 1
                  continue
              elif char == '\n':
                  current_row.append(''.join(current_field))
                  current_field = []
                  rows.append(current_row)
                  current_row = []
                  i += 1
                  continue
              else:
                  current_field.append(char)
                  i += 1
                  continue
      
      # Add the last field/row if exists
      current_row.append(''.join(current_field))
      rows.append(current_row)
      
      # Remove trailing empty row caused by trailing newline
      if rows and len(rows[-1]) == 1 and rows[-1][0] == '' and (text.endswith('\n') or text.endswith('\r')):
          # Check if the last character was a newline that didn't create meaningful data
          # Only remove if the last field was empty and we had a trailing newline
          # But also handle case where text ends with \r\n but we already processed it
          # Our logic adds a row even for trailing newline, so remove that last row
          # Only if that row is effectively empty (just one empty field)
          if len(rows) > 1 and (text.endswith('\r\n') or text.endswith('\n')):
              # Check if the row before last was non-empty or if this is just a continuation
              # Actually simpler: remove last row only if it's empty and we had trailing newline
              # But need to be careful: text = "a\n" should give [['a']], not [['a'], ['']]
              # Our current logic already adds row on newline, so last row might be empty
              # Let's just check if last row is empty and remove it
              # But: text = "" is handled above, text = "\n" should give [['']]?
              # Actually, per spec: "A line break at the very end of the text does not start another row"
              # So "a\n" should give [['a']], not [['a'], ['']]
              # This means we shouldn't have added the empty field in the first place
              # The issue is our logic: we always add a field on newline
              pass
      
      # Actually, let's reconsider the trailing newline case
      # If the text ends with \n or \r\n, that shouldn't create a new row
      # So if the last character(s) are a newline, we should remove the last empty row if it exists
      
      # Better approach: process all but the last newline if trailing
      # Let's handle this differently: when we hit a newline, we add the row, but if it's at the very end, skip adding the row
      
      # Re-implement with cleaner logic
      rows = []
      current_row = []
      current_field = []
      in_quotes = False
      i = 0
      n = len(text)
      
      while i < n:
          char = text[i]
          
          if in_quotes:
              if char == '"':
                  if i + 1 < n and text[i + 1] == '"':
                      current_field.append('"')
                      i += 2
                  else:
                      in_quotes = False
                      i += 1
              else:
                  current_field.append(char)
                  i += 1
          else:
              if char == '"':
                  in_quotes = True
                  i += 1
              elif char == ',':
                  current_row.append(''.join(current_field))
                  current_field = []
                  i += 1
              elif char == '\r':
                  if i + 1 < n and text[i + 1] == '\n':
                      # \r\n case
                      # Check if this is the very end of text
                      if i + 2 == n:
                          # Trailing \r\n - don't create new row
                          current_row.append(''.join(current_field))
                          rows.append(current_row)
                          break
                      else:
                          current_row.append(''.join(current_field))
                          current_field = []
                          rows.append(current_row)
                          current_row = []
                          i += 2
                  else:
                      # Standalone \r (just \r)
                      if i + 1 == n:
                          current_row.append(''.join(current_field))
                          rows.append(current_row)
                          break
                      else:
                          current_row.append(''.join(current_field))
                          current_field = []
                          rows.append(current_row)
                          current_row = []
                          i += 1
              elif char == '\n':
                  # Standalone \n
                  if i + 1 == n:
                      # Trailing \n - don't create new row
                      current_row.append(''.join(current_field))
                      rows.append(current_row)
                      break
                  else:
                      current_row.append(''.join(current_field))
                      current_field = []
                      rows.append(current_row)
                      current_row = []
                      i += 1
              else:
                  current_field.append(char)
                  i += 1
      
      return rows

トークンコスト: $0.02 · 対戦の進行と評価方法について →