Python使用tempfile安全、优雅地处理临时文件与临时目录

with open("/tmp/data.txt", "w") as f:
    f.write("hello")

import os
import time

filename = f"/tmp/{int(time.time())}.txt"
with open(filename, "w") as f:
    f.write("temporary data")

import tempfile

with tempfile.TemporaryFile(mode="w+t", encoding="utf-8") as f:
    f.write("hello tempfile")
    f.seek(0)
    print(f.read())

hello tempfile

tempfile.TemporaryFile(mode='w+b', buffering=-1, encoding=None, newline=None, suffix=None, prefix=None, dir=None)

with tempfile.TemporaryFile() as f:
    f.write("abc")

with tempfile.TemporaryFile() as f:
    f.write(b"abc")

with tempfile.TemporaryFile(mode="w+", encoding="utf-8") as f:
    f.write("abc")

import tempfile

with tempfile.NamedTemporaryFile(mode="w+", encoding="utf-8") as f:
    print("文件路径：", f.name)
    f.write("hello")
    f.seek(0)
    print(f.read())

import tempfile
import pathlib

with tempfile.NamedTemporaryFile(mode="w+", suffix=".txt", encoding="utf-8") as f:
    path = pathlib.Path(f.name)
    f.write("temporary content")
    f.flush()
    print(path.read_text(encoding="utf-8"))

f.flush()

import os
os.fsync(f.fileno())

import tempfile

with tempfile.NamedTemporaryFile(mode="w+", encoding="utf-8") as f:
    print(f.name)
    with open(f.name, "r", encoding="utf-8") as another:
        print(another.read())

import tempfile

with tempfile.NamedTemporaryFile(
    mode="w",
    encoding="utf-8",
    delete=False
) as f:
    temp_name = f.name
    f.write("hello from tempfile")

try:
    with open(temp_name, "r", encoding="utf-8") as reader:
        print(reader.read())
finally:
    import os
    os.unlink(temp_name)

import tempfile
from pathlib import Path

with tempfile.TemporaryDirectory() as temp_dir:
    temp_path = Path(temp_dir)
    file1 = temp_path / "a.txt"
    file2 = temp_path / "b.txt"

    file1.write_text("A", encoding="utf-8")
    file2.write_text("B", encoding="utf-8")

    print(list(temp_path.iterdir()))

import tempfile
from pathlib import Path

def process_files():
    with tempfile.TemporaryDirectory(prefix="myjob_") as temp_dir:
        temp_dir = Path(temp_dir)

        raw_file = temp_dir / "raw.json"
        cleaned_file = temp_dir / "cleaned.json"
        result_file = temp_dir / "result.txt"

        raw_file.write_text('{"name": "python"}', encoding="utf-8")
        cleaned_file.write_text('{"name":"python"}', encoding="utf-8")
        result_file.write_text("done", encoding="utf-8")

        return result_file.read_text(encoding="utf-8")

import tempfile

with tempfile.SpooledTemporaryFile(max_size=1024, mode="w+t", encoding="utf-8") as f:
    f.write("small content")
    f.seek(0)
    print(f.read())

tempfile.SpooledTemporaryFile(max_size=1024 * 1024)

import tempfile

with tempfile.SpooledTemporaryFile(max_size=1024, mode="w+t", encoding="utf-8") as f:
    f.write("hello")
    f.rollover()   # 强制从内存切换到底层文件

import os
import tempfile

fd, path = tempfile.mkstemp(suffix=".log")

try:
    with os.fdopen(fd, "w", encoding="utf-8") as f:
        f.write("log content")
    print(path)
finally:
    os.unlink(path)

import shutil
import tempfile
from pathlib import Path

temp_dir = tempfile.mkdtemp(prefix="demo_")
try:
    path = Path(temp_dir)
    (path / "example.txt").write_text("hello", encoding="utf-8")
    print(path)
finally:
    shutil.rmtree(temp_dir)

tempfile.NamedTemporaryFile()

tempfile.NamedTemporaryFile(suffix=".csv")

tempfile.NamedTemporaryFile(prefix="report_")

tempfile.NamedTemporaryFile(dir="/custom/tmp")

import tempfile

print(tempfile.gettempdir())

import tempfile
print(tempfile.gettempprefix())

import tempfile
import pandas as pd

def handle_uploaded_file(file_obj):
    with tempfile.NamedTemporaryFile(suffix=".csv", delete=False) as temp_file:
        temp_file.write(file_obj.read())
        temp_path = temp_file.name

    try:
        df = pd.read_csv(temp_path)
        return df.head().to_dict()
    finally:
        import os
        os.unlink(temp_path)

import os
import subprocess
import tempfile

with tempfile.NamedTemporaryFile(suffix=".txt", mode="w", encoding="utf-8", delete=False) as input_file:
    input_file.write("Hello subprocess")
    input_path = input_file.name

try:
    result = subprocess.run(
        ["cat", input_path],
        capture_output=True,
        text=True,
        check=True
    )
    print(result.stdout)
finally:
    os.unlink(input_path)

import tempfile
from pathlib import Path

def generate_report(output_dir):
    output_path = Path(output_dir) / "report.txt"
    output_path.write_text("report content", encoding="utf-8")
    return output_path

def test_generate_report():
    with tempfile.TemporaryDirectory() as temp_dir:
        report_path = generate_report(temp_dir)
        assert report_path.exists()
        assert report_path.read_text(encoding="utf-8") == "report content"

import tempfile

def process_stream(chunks):
    with tempfile.SpooledTemporaryFile(max_size=1024 * 1024, mode="w+b") as f:
        for chunk in chunks:
            f.write(chunk)

        f.seek(0)
        return f.read(100)

with tempfile.TemporaryFile() as f:
    f.write("hello")  # 报错

with tempfile.TemporaryFile(mode="w+", encoding="utf-8") as f:
    f.write("hello")

with tempfile.NamedTemporaryFile(mode="w+", encoding="utf-8") as f:
    f.write("data")
    # 这里立刻把路径交给别的逻辑，可能读不到完整内容

f.flush()

import os
os.fsync(f.fileno())

path = None
try:
    with tempfile.NamedTemporaryFile(delete=False) as f:
        path = f.name
    # do something
finally:
    if path:
        import os
        try:
            os.unlink(path)
        except FileNotFoundError:
            pass

f = tempfile.NamedTemporaryFile()
# 依赖垃圾回收自动关闭删除

with tempfile.NamedTemporaryFile() as f:
    ...

filename = f"/tmp/task_{user_id}.txt"

path = "/tmp/my_temp.txt"

with tempfile.TemporaryDirectory() as temp_dir:
    ...

suffix=".json"
suffix=".csv"
suffix=".png"

import os
import tempfile

DEBUG_KEEP_TEMP = os.getenv("DEBUG_KEEP_TEMP") == "1"

temp_file = tempfile.NamedTemporaryFile(delete=not DEBUG_KEEP_TEMP)

import json
import tempfile
from pathlib import Path

def run_pipeline():
    with tempfile.TemporaryDirectory(prefix="pipeline_") as temp_dir:
        temp_dir = Path(temp_dir)

        raw_path = temp_dir / "raw.json"
        cleaned_path = temp_dir / "cleaned.json"
        result_path = temp_dir / "result.txt"

        raw_data = {
            "name": "tempfile",
            "category": "python stdlib",
            "tags": ["file", "temp", "safe"]
        }

        raw_path.write_text(
            json.dumps(raw_data, ensure_ascii=False, indent=2),
            encoding="utf-8"
        )

        data = json.loads(raw_path.read_text(encoding="utf-8"))
        data["tags"] = [tag.upper() for tag in data["tags"]]

        cleaned_path.write_text(
            json.dumps(data, ensure_ascii=False, indent=2),
            encoding="utf-8"
        )

        result_path.write_text(
            f"模块：{data['name']}\n标签数量：{len(data['tags'])}",
            encoding="utf-8"
        )

        return result_path.read_text(encoding="utf-8")

print(run_pipeline())

import tempfile

with tempfile.TemporaryFile(mode="w+t", encoding="utf-8") as f:
    f.write("hello")
    f.seek(0)
    print(f.read())

import tempfile

with tempfile.NamedTemporaryFile(mode="w+t", encoding="utf-8") as f:
    print(f.name)

import tempfile

with tempfile.TemporaryDirectory() as d:
    print(d)

import tempfile

with tempfile.SpooledTemporaryFile(max_size=1024, mode="w+t", encoding="utf-8") as f:
    f.write("hello")

import os
import tempfile

fd, path = tempfile.mkstemp()
try:
    with os.fdopen(fd, "w", encoding="utf-8") as f:
        f.write("hello")
finally:
    os.unlink(path)