Hey there! Let's break down why you're hitting that syntax error on your with tf.Session() as sess: line and how to fix it right away.

Common Causes & Solutions #

1. You're using TensorFlow 2.x (which drops tf.Session() by default) #

TensorFlow 2.x switched to Eager Execution as its default mode—this means you don't need to wrap your code in a Session anymore. If you're running old TF1.x-style code in TF2.x, you have two straightforward fixes:

Option A: Use TF1.x compatibility mode

Update your code to use the compatibility module to retain the session workflow:

import tensorflow as tf

# Disable eager execution to mimic TF1.x behavior
tf.compat.v1.disable_eager_execution()

# Use the compatible Session class
with tf.compat.v1.Session() as sess:
    # Your code logic here (e.g., sess.run(your_tensor))

Option B: Migrate to TF2.x native syntax

Ditch the session entirely—just run tensor operations directly. For example, if you had this old code:

# TF1.x code
a = tf.constant(10)
with tf.Session() as sess:
    print(sess.run(a))

In TF2.x, this simplifies to:

# TF2.x code
a = tf.constant(10)
print(a.numpy())  # Or even just print(a) — TF2.x displays tensors directly

2. You have an indentation or syntax typo #

Syntax errors can also pop up from small oversights:

• The code block under your with statement isn't properly indented (Python requires consistent indentation for code blocks)
• There's a missing parenthesis, colon, or syntax mistake in the lines immediately before the with statement

Double-check your code for these issues—here's a correctly indented example:

# Correct indentation example
with tf.Session() as sess:
    # Indent this line (4 spaces or 1 tab)
    result = sess.run(your_operation)
    print(result)

内容的提问来源于stack exchange，提问作者Shrinidhi Goswami